Jessica Austriaco

 is our pivotal efficacy study to demonstrate lifespan and healthspan extension in senior dogs treated with LOY-002. This is the biggest study of its kind ever conducted — we’re partnering with more than 50 independent veterinary clinics across the country.

These sites will enroll 1,000 senior dogs as part of this study. Here’s how to get your dog involved.

To participate in this study, your dog must meet several specific requirements. These requirements are necessary to ensure the scientific integrity of our study, so we’re not able to make any exceptions.

If you meet these requirements, your dog will undergo screening at a study site to confirm their eligibility.

The study will be conducted at 55 sites across the country. We’ll be opening these sites for enrollment in several phases over the coming months.

To see if we’re anticipating a site near you, review our 

. This map shows all planned sites for the STAY study, and displays contact details for sites that are currently open for enrollment.

If you don’t find a site near you, we encourage you to join the 

 for announcements on future studies and product availability.

Here are our upcoming sites, which will be updated with contact information in the site map when their clinic begins enrollment.

If there’s a site near you that’s open for enrollment, you can contact them directly at the address or phone number provided.

Let them know your dog’s age and weight and they’ll work with you to schedule a screening visit to determine your dog’s eligibility.

Enrolling your dog in the STAY study

The <a href="https://loyalfordogs.com/clinical-trials">STAY study</a> is our pivotal efficacy study to demonstrate lifespan and healthspan extension in senior dogs treated with LOY-002. This is the biggest study of its kind ever conducted — we’re partnering with more than 50 independent veterinary clinics across the country.



These sites will enroll 1,000 senior dogs as part of this study. Here’s how to get your dog involved.







<h2 class="wp-block-heading has-large-font-size">Eligibility</h2>



To participate in this study, your dog must meet several specific requirements. These requirements are necessary to ensure the scientific integrity of our study, so we’re not able to make any exceptions.



To enroll your dog:



<ol class="wp-block-list">
<li>They must be 10 years or older with proof of age. Acceptable documentation includes: breeding records or registrations, shelter adoption records for puppies less than six months old at the time of adoption, an examination by a veterinarian conducted when the dog was estimated to be one year old or younger, neutering records when the dog was estimated to be one year old or younger, other forms of verification that validate the dog’s age within a year, such as time-stamped puppy photos, photos that can be referenced with members of the family at a known age, or other time-specific documentation, at the discretion of the study investigator.</li>



<li>They must weigh at least 14 pounds.</li>



<li>You must be willing and able to participate for the full four-year duration of the study.</li>



<li>You must live near&nbsp;<a href="https://loyalfordogs.com/clinical-trials#participate" target="_blank" rel="noreferrer noopener">a study site</a>.</li>
</ol>



If you meet these requirements, your dog will undergo screening at a study site to confirm their eligibility.







<h2 class="wp-block-heading has-large-font-size">Sites open for enrollment</h2>



The study will be conducted at 55 sites across the country. We’ll be opening these sites for enrollment in several phases over the coming months.



To see if we’re anticipating a site near you, review our&nbsp;<a target="_blank" href="https://loyalfordogs.com/clinical-trials#participate" rel="noreferrer noopener">interactive site map</a>. This map shows all planned sites for the STAY study, and displays contact details for sites that are currently open for enrollment.



If you don’t find a site near you, we encourage you to join the&nbsp;<a href="https://loyalfordogs.com/#join" target="_blank" rel="noreferrer noopener">Loyal list</a>&nbsp;for announcements on future studies and product availability.



<h2 class="wp-block-heading has-large-font-size">Upcoming sites</h2>



Here are our upcoming sites, which will be updated with contact information in the site map when their clinic begins enrollment.



End of April



<ul class="wp-block-list">
<li>Folsom, Louisiana</li>



<li>Conyers, Georgia</li>
</ul>



End of May



<ul class="wp-block-list">
<li>Liverpool, New York</li>



<li>Midlothian, Virginia</li>



<li>Hendersonville, North Carolina</li>



<li>Columbia, South Carolina</li>



<li>Pensacola, Florida</li>



<li>Glenpool, Oklahoma</li>



<li>Bowie, Texas</li>



<li>Denver, Colorado</li>
</ul>



End of June



<ul class="wp-block-list">
<li>Waltham, Massachusetts</li>



<li>Chattanooga, Tennessee</li>



<li>Perkins, Oklahoma</li>



<li>Carrollton, Texas</li>



<li>Monument, Colorado</li>
</ul>



End of July



<ul class="wp-block-list">
<li>Virginia Beach, Virginia</li>
</ul>



This summer



<ul class="wp-block-list">
<li>Hoboken, New Jersey</li>



<li>Sandy Spring, Maryland</li>



<li>Starke, Florida</li>



<li>Land O’ Lakes, Florida</li>



<li>Quincy, Florida</li>



<li>Reedsburg, Wisconsin</li>



<li>Carbondale, Illinois</li>



<li>Batavia, Ohio</li>



<li>Nicholasville, Kentucky</li>



<li>Omaha, Nebraska</li>



<li>Lincoln, Nebraska</li>



<li>Papillion, Nebraska</li>



<li>Lindale, Texas</li>



<li>El Paso, Texas</li>



<li>Los Altos, California</li>



<li>Los Gatos, California</li>



<li>Norco, California</li>
</ul>



<h2 class="wp-block-heading has-large-font-size">How to get started</h2>



If there’s a site near you that’s open for enrollment, you can contact them directly at the address or phone number provided.



Let them know your dog’s age and weight and they’ll work with you to schedule a screening visit to determine your dog’s eligibility.



We’ll update our&nbsp;<a href="https://loyalfordogs.com/clinical-trials#map" target="_blank" rel="noreferrer noopener">site map</a>&nbsp;as new sites come online.

Karen Greenwood

Some important news: Loyal has received protocol concurrence from the FDA on our companion dog longevity study. This means that the FDA has reviewed the scientific design of our study and determined that it meets their high quality standards, and will validate whether our drug extends canine lifespan and 

In other words, if our study demonstrates that our dog longevity drug extends healthy lifespan, those results will be sufficient to support bringing the drug to market for dogs across the country. 

_________________________________________

Our concurrence means we fundamentally agree with your proposed design, execution, and analyses…

This is a huge milestone for any drug company, but it’s especially significant because, to our knowledge, this is the first time the FDA has accepted a clinical study intending to show that a drug extends lifespan and healthspan, rather than only proving efficacy against a single, specific disease — which is the case with most drugs on the market today.

Loyal was founded around the audacious idea that we should have drugs explicitly designed and FDA-approved to extend general healthy lifespan. With this milestone we take another big step in the direction of this vision. 

To achieve this milestone, we worked with scientists and statisticians at the 

 CVM— the division of the FDA responsible for overseeing the medicines we give our pets — to interrogate and optimize our study design.

We and the CVM have a shared interest in making sure our study is designed in a way that proves whether our products are effective and safe; both are paramount, scientifically and ethically.

Protocol concurrence is a huge step, but it’s not a guarantee

While we’re energized by this milestone, there’s still a lot of hard and careful work to be done.

Clinical trials are complex, and although we strive always to make scientific, evidence-based decisions in our study design and treatments, we won’t actually know how a drug will perform at scale in the real world until we run the study.

What looks promising and effective in a laboratory must in turn be proven in the field — the real world, where dogs live alongside us, and under the supervision of veterinarians in a clinical setting. This is the purpose of clinical trials.

If the study doesn’t deliver a positive outcome, we won’t — and shouldn’t — get approval. 

Designing a study to prove lifespan extension

Clinical studies are sometimes straightforward and sometimes complex. A study to show whether a new flea and tick treatment works can take much less time to design and conduct, since there are many previous studies showing how to measure the efficacy of these drugs.

Ours has been a much longer process — a total of 553 days, just over 18 months, from first discussion on the program to protocol concurrence.

We believe we’re the first to design and receive FDA concurrence for a clinical study that measures lifespan extension following treatment of the underlying causes of aging, rather than any specific disease.

We’re actively recruiting veterinary practices across the country to run clinical trials later this year. If you’re interested in partnering with us on this groundbreaking study, get in touch with our veterinary team today.

We often are asked why we aren’t working on dog aging supplements.

At Loyal we made the decision from the start that we would seek FDA approval for our aging drugs. It’s a rigorous, expensive, years-long process that sets a very high bar for both safety and efficacy — exactly as it should be.

Supplements have no such obligation, and even if they do run their own studies, there’s no oversight. This is why you’ll see a “These statements have not been evaluated by the FDA” disclaimer in fine print on supplements for dogs and humans alike.

While supplements may not hurt and might help your dog, there’s no process to regulate or validate the claims they make on their label, so you can’t be sure of a supplement’s safety or effectiveness.

And for us, especially when our dogs are involved, that just isn’t good enough.

Be the first to know when we’re recruiting dogs for our study

Karen is Loyal’s Senior Vice President of Regulatory & Strategy, and brings more than three decades of animal pharmaceutical experience to the company. She spent 27 years in 

 before going on to oversee programs at leading animal pharmaceutical companies including 

Loyal’s latest milestone: the first longevity clinical study design supported by the FDA

Some important news: Loyal has received protocol concurrence from the FDA on our companion dog longevity study. This means that the FDA has reviewed the scientific design of our study and determined that it meets their high quality standards, and will validate whether our drug extends canine lifespan and <a href="https://blog-admin.loyalfordogs.com/how-scientists-measure-aging-through-healthspan-frailty-and-quality-of-life/" data-type="URL" data-id="https://blog-admin.loyalfordogs.com/how-scientists-measure-aging-through-healthspan-frailty-and-quality-of-life/">healthspan</a>.



In other words, if our study demonstrates that our dog longevity drug extends healthy lifespan, those results will be sufficient to support bringing the drug to market for dogs across the country. 



_________________________________________



<h2 class="wp-block-heading has-text-align-center has-regular-font-size">Our concurrence means we fundamentally agree with your proposed design, execution, and analyses…</h2>



– FDA CENTER FOR VETERINARY MEDICINE



_________________________________________



This is a huge milestone for any drug company, but it’s especially significant because, to our knowledge, this is the first time the FDA has accepted a clinical study intending to show that a drug extends lifespan and healthspan, rather than only proving efficacy against a single, specific disease — which is the case with most drugs on the market today.



Loyal was founded around the audacious idea that we should have drugs explicitly designed and FDA-approved to extend general healthy lifespan. With this milestone we take another big step in the direction of this vision.&nbsp;



To achieve this milestone, we worked with scientists and statisticians at the <a href="https://www.fda.gov/about-fda/fda-organization/center-veterinary-medicine" data-type="URL" data-id="https://www.fda.gov/about-fda/fda-organization/center-veterinary-medicine">Center for Veterinary Medicine</a> CVM— the division of the FDA responsible for overseeing the medicines we give our pets — to interrogate and optimize our study design.



We and the CVM have a shared interest in making sure our study is designed in a way that proves whether our products are effective and safe; both are paramount, scientifically and ethically.











<h2 class="wp-block-heading has-large-font-size" id="protocol-concurrence-is-a-huge-step-but-it-s-not-a-guarantee" style="font-style:normal;font-weight:600">Protocol concurrence is a huge step, but it’s not a guarantee</h2>



While we’re energized by this milestone, there’s still a lot of hard and careful work to be done.



Clinical trials are complex, and although we strive always to make scientific, evidence-based decisions in our study design and treatments, we won’t actually know how a drug will perform at scale in the real world until we run the study.



What looks promising and effective in a laboratory must in turn be proven in the field — the real world, where dogs live alongside us, and under the supervision of veterinarians in a clinical setting. This is the purpose of clinical trials.



If the study doesn’t deliver a positive outcome, we won’t — and shouldn’t — get approval.&nbsp;











<h2 class="wp-block-heading has-large-font-size" id="designing-a-study-to-prove-lifespan-extension" style="font-style:normal;font-weight:600">Designing a study to prove lifespan extension</h2>



Clinical studies are sometimes straightforward and sometimes complex. A study to show whether a new flea and tick treatment works can take much less time to design and conduct, since there are many previous studies showing how to measure the efficacy of these drugs.



Ours has been a much longer process —&nbsp;a total of 553 days, just over 18 months, from first discussion on the program to protocol concurrence.



We believe we’re the first to design and receive FDA concurrence for a clinical study that measures lifespan extension following treatment of the underlying causes of aging, rather than any specific disease.



We’re actively recruiting veterinary practices across the country to run clinical trials later this year. If you’re interested in partnering with us on this groundbreaking study, get in touch with our veterinary team today.



→ <a href="https://loyalfordogs.com/for-vets/">Become a clinical trial site</a>











<h2 class="wp-block-heading has-large-font-size" id="why-fda-approval-is-so-important" style="font-style:normal;font-weight:600">Why FDA approval is so important</h2>



We often are asked why we aren’t working on dog aging supplements.



At Loyal we made the decision from the start that we would seek FDA approval for our aging drugs. It’s a rigorous, expensive, years-long process that sets a very high bar for both safety and efficacy — exactly as it should be.



Supplements have no such obligation, and even if they do run their own studies, there’s no oversight. This is why you’ll see a “These statements have not been evaluated by the FDA” disclaimer in fine print on supplements for dogs and humans alike.



While supplements may not hurt and might help your dog, there’s no process to regulate or validate the claims they make on their label, so you can’t be sure of a supplement&#8217;s safety or effectiveness.



And for us, especially when our dogs are involved, that just isn’t good enough.











<h2 class="wp-block-heading has-large-font-size" id="be-the-first-to-know-when-we-re-recruiting-dogs-for-our-study" style="font-style:normal;font-weight:600">Be the first to know when we’re recruiting dogs for our study </h2>



<h2 class="wp-block-heading has-large-font-size" id="be-the-first-to-know-when-we-re-recruiting-dogs-for-our-study" style="font-style:normal;font-weight:600">→ <a href="https://loyalfordogs.com/#join">Join our list today</a></h2>







<figure class="wp-block-image size-large is-resized"><img loading="lazy" decoding="async" width="1024" height="683" src="http://blog-admin.loyalfordogs.com/wp-content/uploads/2023/03/DSC02606-1024x683.jpg" alt="" class="wp-image-735" style="width:695px;height:464px" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/03/DSC02606-1024x683.jpg 1024w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/03/DSC02606-300x200.jpg 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/03/DSC02606-768x512.jpg 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/03/DSC02606-1536x1024.jpg 1536w" sizes="(max-width: 1024px) 100vw, 1024px" /></figure>



Karen is Loyal’s Senior Vice President of Regulatory &amp; Strategy, and brings more than three decades of animal pharmaceutical experience to the company. She spent 27 years in <a href="https://www.pfizer.com/content/animal-health" data-type="URL" data-id="https://www.pfizer.com/content/animal-health">Pfizer’s Animal Health</a> group and <a href="https://www.zoetis.com/" data-type="URL" data-id="https://www.zoetis.com/">Zoetis</a> before going on to oversee programs at leading animal pharmaceutical companies including <a href="https://parnell.com/" data-type="URL" data-id="https://parnell.com/">Parnell</a> and <a href="https://ir.kindredbio.com/" data-type="URL" data-id="https://ir.kindredbio.com/">KindredBio</a>.

Brennen McKenzie, MA, MSc, VMD

published the results of our Healthspan study

, the first clinical study assessing two tools for measuring frailty and health-related quality of life in dogs.

Dogs are a unique translational model of aging. By understanding aging in dogs, we learn how to better treat aging in both dogs and humans. We observed groups of young and old dogs and small and large dogs using a veterinarian assessment tool — the Canine Frailty Index, or CFI — to measure frailty and an owner assessment — VetMetrica’s Health-Related Quality of Life (HRQL) questionnaire — to measure quality of life.

Our core mission here at Loyal is to give people and their dogs more time together. By targeting the underlying mechanisms of aging, we are working to help dogs live longer. But for that to be a truly worthwhile goal, we have to do more. We have to make that additional time enjoyable and worth living. 

Studying healthspan aims to measure dogs’ function towards their end-of-life

We want to extend lifespan but it is critical that we extend 

healthspan, the period of time dogs are living healthy lives

, too. We want dogs to live healthy lives for as long as possible, before aging has diminished their function or quality of life. 

Frailty is a state of increased vulnerability to disease and death. Health-related quality of life is a measure of the impact health problems have on overall wellbeing. These two facets of aging are commonly measured in older humans to help guide lifestyle and healthcare decisions.

Veterinarians are only just beginning to give more consideration to how frailty and the impact of health problems on quality of life are manifestations of the aging process in dogs, and the tools to measure these are not yet in routine clinical use.

What tools were used to evaluate frailty and quality of life?

We used two existing tools for evaluating older dogs; the Canine Frailty Index (CFI) and the 

Vetmetrica Health-related Quality of Life

Using the CFI, a veterinarian can evaluate a wide range of age-related problems and assess the overall impact of aging on the health and function of an individual dog.

The HRQL is a questionnaire that assesses owners’ perceptions of their dog’s quality of life. It evaluates this in several different domains, including energy and enthusiasm, happiness and contentment, calmness and relaxation, and the dog’s level of comfort and activity.

A graphical summary of the Healthspan study

Who participated and how did we run the study?

In our Healthspan study, Loyal recruited 586 dogs from across the United States.

We had 84 different breeds — representatives of the purebred Cane Corso, French Bulldog, and Great Dane; and many Boxers, Australian Shepherds, Golden Retrievers, poodles, doodles and supermutts.

We saw dogs from 2 years old to 18, and dogs ranging from less than 15 to over 120 pounds. We even enrolled a tiny dog just under 3 pounds and a giant 175-pound dog.

We analyzed 451 of these dogs to test how well the CFI and HRQL tools measured the effects of aging in both young and old dogs. We also compared small and large dogs using these tools, to better understand the different way aging impacts dogs of different sizes. 

The dogs in the Healthspan Study came with their owners to our clinical sites for an examination and collection of blood samples. These sites were at small private veterinary hospitals, large academic medical centers, and even our innovative “pop-up” mobile clinical site. The dog owners in the study also answered detailed questions about their health. 

Our results: frailty in old and young dogs

Using this information, we were able to show that the CFI is a sensitive tool for detecting the negative health impact of aging on dogs. These scores were higher in the old dog group and began to increase after 7 years of age.

CFI scores increased with age in older dogs but are stable in younger dogs. Based on Figure 4 

Our results: quality of life in old and young dogs

We were also able to confirm that the HRQL is an effective measure of the impact of aging on health and quality of life. Generally, we found that HRQL scores decreased with age. HRQL scores were lower in older dogs than in the younger group due to the accumulation of age-related health problems and the effects of these problems on the overall quality of life in these dogs.  Just as with the CFI, the scores for the HRQL got worse with age in the older dogs but stayed at a better level in the younger, healthier dogs.

HRQL total scores decrease with age. Total scores are shown in young/old small (blue) and young/old large dogs (red) through these box and whisker plots. Boxes demonstrate the center and spread of scores in each group. The horizontal bars demonstrate the groups that are significantly different from each other. The study had some outlier values, indicated by the dots. Based on Figure 5a 

Our results: quality of life in large and small dogs

When we analyzed the different components of the HRQL, we also found that there were some differences between large and small dogs. It is well-known that 

large dogs have shorter lives than smaller dogs

, and it is believed this is because they experience the negative health effects of aging sooner and more severely. 

The HRQL’s four domains include energy and enthusiasm, happiness and contentment, calmness and relaxation, and the dog’s level of comfort and activity. We observed HRQL scores are stable in young dogs, but starting at age 7, old dogs show yearly declines in HRQL scores across most domains. 

We were able to show, for the first time, significant differences in activity and comfort between older large and small dogs. All dogs experience a decline in activity and perceived comfort as they age, but this decline is faster in bigger dogs, as measured by the Active/Comfortable component of the HRQL.

HRQL scores are stable in young dogs, but starting at age 7, old dogs show yearly declines in HRQL scores across most domains. In activity and comfort scores, we observed that larger dogs showed faster yearly declines compared to small dogs. Based on Figure 6b 

Another important finding of the Healthspan study was that the CFI and HRQL both identified the same age-related changes even though the CFI was a medical assessment by a veterinarian and the HRQL was a questionnaire evaluating the owners’ perceptions of their dogs at home. This consistency is strong evidence that the tools are both measuring the same underlying process—that is aging! 

These complementary tools can also be used to help better understand the details of the aging process in dogs. For example, the fact that larger dogs showed a greater decline in the Active/Comfortable component of the HRQL makes sense when we see that in the list of diseases that make up the CFI, arthritis was more common among the large old dogs than among the smaller dogs. It is likely that the earlier and more rapid development of this common age-related health problem may be part of the explanation for why this aspect of health-related quality of life declines faster in bigger dogs. 

How the Healthspan study builds on the Loyal mission

Building on the success of the Healthspan study, Loyal will use the HRQL and the CFI in future studies to help us better understand canine aging and evaluate the impact of our drugs on healthspan in aging dogs. Helping vets and dog owners to measure the effects of aging on dogs and developing drugs that can slow aging mechanisms are critical to our core mission of extending lifespan and healthspan in dogs and giving people and their canine companions more joyful time together.

Read the full publication in GeroScience.

 Evaluating instruments for assessing healthspan: a multi-center cross-sectional study on health-related quality of life (HRQL) and frailty in the companion dog. 

https://doi.org/10.1007/s11357-023-00744-2

How scientists measure aging through Healthspan, frailty and quality of life

Loyal has just <a href="https://link.springer.com/article/10.1007/s11357-023-00744-2">published the results of our Healthspan study</a>, the first clinical study assessing two tools for measuring frailty and health-related quality of life in dogs.



Dogs are a unique translational model of aging. By understanding aging in dogs, we learn how to better treat aging in both dogs and humans. We observed groups of young and old dogs and small and large dogs using a veterinarian assessment tool — the Canine Frailty Index, or CFI — to measure frailty and an owner assessment — VetMetrica’s Health-Related Quality of Life (HRQL) questionnaire — to measure quality of life.



Our core mission here at Loyal is to give people and their dogs more time together. By targeting the underlying mechanisms of aging, we are working to help dogs live longer. But for that to be a truly worthwhile goal, we have to do more. We have to make that additional time enjoyable and worth living. 







<h2 class="wp-block-heading" id="studying-healthspan-aims-to-measure-dogs-function-towards-their-end-of-life" style="font-style:normal;font-weight:600">Studying healthspan aims to measure dogs&#8217; function towards their end-of-life</h2>



We want to extend lifespan but it is critical that we extend <a href="https://blog-admin.loyalfordogs.com/healthspan-the-healthy-prime-of-life/">healthspan, the period of time dogs are living healthy lives</a>, too. We want dogs to live healthy lives for as long as possible, before aging has diminished their function or quality of life.&nbsp;



Frailty is a state of increased vulnerability to disease and death. Health-related quality of life is a measure of the impact health problems have on overall wellbeing. These two facets of aging are commonly measured in older humans to help guide lifestyle and healthcare decisions. 



Veterinarians are only just beginning to give more consideration to how frailty and the impact of health problems on quality of life are manifestations of the aging process in dogs, and the tools to measure these are not yet in routine clinical use.







<h2 class="wp-block-heading" id="what-tools-were-used-to-evaluate-frailty-and-quality-of-life" style="font-style:normal;font-weight:600">What tools were used to evaluate frailty and quality of life?</h2>



We used two existing tools for evaluating older dogs; the Canine Frailty Index (CFI) and the <a href="https://www.newmetrica.com/vetmetrica-hrql/">Vetmetrica Health-related Quality of Life</a> questionnaire. 



Using the CFI, a veterinarian can evaluate a wide range of age-related problems and assess the overall impact of aging on the health and function of an individual dog. 



The HRQL is a questionnaire that assesses owners’ perceptions of their dog’s quality of life. It evaluates this in several different domains, including energy and enthusiasm, happiness and contentment, calmness and relaxation, and the dog’s level of comfort and activity.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="934" height="1024" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/Fig9_graphicalsummary_20220711-1-934x1024.png" alt="" class="wp-image-686" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/Fig9_graphicalsummary_20220711-1-934x1024.png 934w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/Fig9_graphicalsummary_20220711-1-274x300.png 274w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/Fig9_graphicalsummary_20220711-1-768x842.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/Fig9_graphicalsummary_20220711-1-1401x1536.png 1401w" sizes="(max-width: 934px) 100vw, 934px" /><figcaption>A graphical summary of the Healthspan study</figcaption></figure>







<h2 class="wp-block-heading" id="who-participated-and-how-did-we-run-the-study" style="font-style:normal;font-weight:600">Who participated and how did we run the study?</h2>



In our Healthspan study, Loyal recruited 586 dogs from across the United States.



We had 84 different breeds — representatives of the purebred Cane Corso, French Bulldog, and Great Dane; and many Boxers, Australian Shepherds, Golden Retrievers, poodles, doodles and supermutts. 



We saw dogs from 2 years old to 18, and dogs ranging from less than 15 to over 120 pounds. We even enrolled a tiny dog just under 3 pounds and a giant 175-pound dog. 



We analyzed 451 of these dogs to test how well the CFI and HRQL tools measured the effects of aging in both young and old dogs. We also compared small and large dogs using these tools, to better understand the different way aging impacts dogs of different sizes.&nbsp;



The dogs in the Healthspan Study came with their owners to our clinical sites for an examination and collection of blood samples. These sites were at small private veterinary hospitals, large academic medical centers, and even our innovative “pop-up” mobile clinical site. The dog owners in the study also answered detailed questions about their health.&nbsp;







<h2 class="wp-block-heading" id="our-results-frailty-in-old-and-young-dogs" style="font-style:normal;font-weight:600">Our results: frailty in old and young dogs</h2>



Using this information, we were able to show that the CFI is a sensitive tool for detecting the negative health impact of aging on dogs. These scores were higher in the old dog group and began to increase after 7 years of age.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="912" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs-1024x912.png" alt="" class="wp-image-688" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs-1024x912.png 1024w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs-300x267.png 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs-768x684.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs-1536x1368.png 1536w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/CFI-scores-increased-with-age-in-older-dogs-but-not-younger-dogs.png 2028w" sizes="(max-width: 1024px) 100vw, 1024px" /><figcaption>CFI scores increased with age in older dogs but are stable in younger dogs. Based on Figure 4 <a href="https://link.springer.com/article/10.1007/s11357-023-00744-2">from the study publication</a></figcaption></figure>







<h2 class="wp-block-heading" id="our-results-quality-of-life-in-old-and-young-dogs" style="font-style:normal;font-weight:600">Our results: quality of life in old and young dogs</h2>



We were also able to confirm that the HRQL is an effective measure of the impact of aging on health and quality of life. Generally, we found that HRQL scores decreased with age. HRQL scores were lower in older dogs than in the younger group due to the accumulation of age-related health problems and the effects of these problems on the overall quality of life in these dogs.&nbsp; Just as with the CFI, the scores for the HRQL got worse with age in the older dogs but stayed at a better level in the younger, healthier dogs.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1013" height="1024" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1-1013x1024.png" alt="" class="wp-image-689" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1-1013x1024.png 1013w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1-297x300.png 297w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1-768x776.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1-1520x1536.png 1520w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-total-scores-decrease-with-age-1.png 2004w" sizes="(max-width: 1013px) 100vw, 1013px" /><figcaption>HRQL total scores decrease with age. Total scores are shown in young/old small (blue) and young/old large dogs (red) through these box and whisker plots. Boxes demonstrate the center and spread of scores in each group. The horizontal bars demonstrate the groups that are significantly different from each other. The study had some outlier values, indicated by the dots. Based on Figure 5a <a href="https://link.springer.com/article/10.1007/s11357-023-00744-2">from the study publication</a></figcaption></figure>







<h2 class="wp-block-heading" id="our-results-quality-of-life-in-large-and-small-dogs" style="font-style:normal;font-weight:600">Our results: quality of life in large and small dogs</h2>



When we analyzed the different components of the HRQL, we also found that there were some differences between large and small dogs. It is well-known that <a href="https://blog-admin.loyalfordogs.com/why-do-big-dogs-have-unusually-short-lifespans-compared-to-small-dogs/">large dogs have shorter lives than smaller dogs</a>, and it is believed this is because they experience the negative health effects of aging sooner and more severely.&nbsp;



The HRQL’s four domains include energy and enthusiasm, happiness and contentment, calmness and relaxation, and the dog’s level of comfort and activity. We observed HRQL scores are stable in young dogs, but starting at age 7, old dogs show yearly declines in HRQL scores across most domains.&nbsp;



We were able to show, for the first time, significant differences in activity and comfort between older large and small dogs. All dogs experience a decline in activity and perceived comfort as they age, but this decline is faster in bigger dogs, as measured by the Active/Comfortable component of the HRQL.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="905" height="1024" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-905x1024.png" alt="" class="wp-image-690" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-905x1024.png 905w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-265x300.png 265w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-768x869.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-1357x1536.png 1357w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1-1810x2048.png 1810w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2023/02/HRQL-scores-declined-with-age-in-old-dogs-but-not-in-young-dogs-1.png 2004w" sizes="(max-width: 905px) 100vw, 905px" /><figcaption>HRQL scores are stable in young dogs, but starting at age 7, old dogs show yearly declines in HRQL scores across most domains. In activity and comfort scores, we observed that larger dogs showed faster yearly declines compared to small dogs. Based on Figure 6b <a href="https://link.springer.com/article/10.1007/s11357-023-00744-2">from the study publication</a></figcaption></figure>







<h2 class="wp-block-heading" id="vet-assessments-vs-owner-questionnaires" style="font-style:normal;font-weight:600">Vet assessments vs owner questionnaires</h2>



Another important finding of the Healthspan study was that the CFI and HRQL both identified the same age-related changes even though the CFI was a medical assessment by a veterinarian and the HRQL was a questionnaire evaluating the owners’ perceptions of their dogs at home. This consistency is strong evidence that the tools are both measuring the same underlying process—that is aging!&nbsp;



These complementary tools can also be used to help better understand the details of the aging process in dogs. For example, the fact that larger dogs showed a greater decline in the Active/Comfortable component of the HRQL makes sense when we see that in the list of diseases that make up the CFI, arthritis was more common among the large old dogs than among the smaller dogs. It is likely that the earlier and more rapid development of this common age-related health problem may be part of the explanation for why this aspect of health-related quality of life declines faster in bigger dogs.&nbsp;







<h2 class="wp-block-heading" id="how-the-healthspan-study-builds-on-the-loyal-mission" style="font-style:normal;font-weight:600">How the Healthspan study builds on the Loyal mission</h2>



Building on the success of the Healthspan study, Loyal will use the HRQL and the CFI in future studies to help us better understand canine aging and evaluate the impact of our drugs on healthspan in aging dogs. Helping vets and dog owners to measure the effects of aging on dogs and developing drugs that can slow aging mechanisms are critical to our core mission of extending lifespan and healthspan in dogs and giving people and their canine companions more joyful time together.



<h2 class="has-xl-font-size wp-block-heading" id="read-the-full-publication-in-geroscience" style="font-style:normal;font-weight:600"> → <a href="https://link.springer.com/article/10.1007/s11357-023-00744-2">Read the full publication in GeroScience.</a></h2>







<h2 class="wp-block-heading" id="sources" style="font-style:normal;font-weight:600">Sources</h2>



Chen, F.L., Ullal, T.V., Graves, J.L. et al. Evaluating instruments for assessing healthspan: a multi-center cross-sectional study on health-related quality of life (HRQL) and frailty in the companion dog. GeroScience (2023). <a href="https://doi.org/10.1007/s11357-023-00744-2">https://doi.org/10.1007/s11357-023-00744-2</a>

Loyal

We know biological samples can tell us about our dog’s health and breed ancestry, but is the saliva in your dog’s mouth enough to tell us your dog’s age and birthday? The answer is, in some ways, yes.

—XTD for short—we collected saliva samples from roughly 1,600 dogs of 187 different breeds in 48 US states and health information from their science-loving humans, including a dog named Mazel and his pet parent Abigail. One aspect of this project was measuring DNA methylation and determining a methylation age—a measure of the impact of lifestyle, diet and environment on a dog’s health and longevity.

This is important in several ways. For dogs that were adopted as adults and who have unknown birthdays, determining methylation age might give us a more accurate estimate of chronological age, and help us make choices about preventative healthcare. And someday, with further research, methylation age might help us not only measure the impact of lifestyle and environment of healthspan and lifespan but guide us in making healthier lifestyle and nutritional choices for our dogs. For all dogs, using information directly from a dog’s biology allows you to use snippets of insights over time to evaluate the impact of your dog’s lifestyle and environment on their health and aging.

Mazel is a study participant with an unknown age

Mazel is a brilliant and energetic 10 lb. mixed breed dog with a long back, who resembles a terrier. He was adopted from a shelter in July 2010 as a young adult, but his true age and birthday is unknown. Mazel loves hiking in the hills and exploring, but he’s slowing down and not chasing rabbits anymore. 

Abigail, Mazel’s pet parent, describes him at his current age as “sometimes a little arthritic.” She says, “He’s one of those dogs who is longer than he is tall, and he will throw out his back sometimes. That limits him.”

He seemed pretty young, but no one knew his age for certain. Like most dogs with unknown backgrounds, guesses from friends and family—and even from the vet—might all be different. Since the risk of health problems in dogs grows with age, it would be helpful to have a more accurate way to estimate how old dogs like Mazel really are.

X-Thousand Dogs builds our understanding of aging through epigenetics and methylation

One possible way of doing this is through 

. The passage of time and environmental factors change the structure of our dogs’ DNA in ways that influence how their genes work. One such change is 

methylation, the process where methyl groups are added to DNA 

DNA methylation changes when a methyl group is added or removed to CpG sites. These changes allow us to observe the impact of lifestyle and the environment on dogs as they age

Methylation age is closely related to chronological age,and both increase steadily with time. Unlike chronological age, which depends only on time, methylation age reflects the impact of environment, diet, and many other factors on a dog’s DNA. This is why the methylation age and chronological age are usually different for any individual dog. In our XTD study results, we call methylation age the estimated age.

The XTD study was able to show that methylation age can predict chronological age in dogs. Using the largest methylation dataset in dogs to date, we built on previous research to confirm that changes in DNA over time can tell us the chronological age of dogs when we don’t know their date of birth.

Based on information from the shelter, Abigail estimates that Mazel was born in August 2009, but she’d always suspected he was older. When she swabbed Mazel earlier this year for XTD, Mazel’s methylation age was 9 months younger than his reported age. The model suggests Mazel’s age is closer to 12 years and 3 months. Rather than older, Mazel was actually younger than the shelter and Abigail expected.

Mazel’s age prediction results from X-Thousand Dogs—you can see his estimated methylation age on the vertical axis and reported age from his pet parent Abigail on the horizontal axis

While it’s useful to know how old a dog is more precisely than just a guess based on how he or she looks, chronological age isn’t a perfect predictor of health status. Age affects every dog differently. Just as there are people running marathons in their 80s while others experience serious age-related health problems much younger, some dogs are healthier and stronger than others at the same age.

Beyond chronological age, it would be useful for vets and dog owners to have a reliable measure of age, how much age has affected a particular dog, and what their risk of age-related health problems truly is.

What does methylation age prediction mean for my dog’s health?

It’s possible that methylation age may reflect environmental factors and their impact on health status better than the length of time a dog has lived. Because methylation age is influenced by environmental and lifestyle factors, not just time, it could tell us more about the health status of individual dogs than their chronological age does. This measure of age through methylation could guide us in decisions about medical tests and treatments, diet, activity levels, and other factors that might extend 

Methylation will likely be an important component of measuring aging, and in adding to our understanding of this process in dogs, the XTD study has opened up more avenues of research for exploration into early cancer detection and environmental factors that impact DNA methylation and aging.

Our X-Thousand Dogs study explored other health-related factors, such as the oral microbiome

In addition to looking at methylation, the saliva samples we collected in the XTD study allowed us to analyze the oral microbiome of participants—the population of bacteria that live in the mouth. These bacteria can perform important roles in promoting health, but imbalances in the oral ecosystem can also increase the risk of disease. For example, 

The population of bacteria in the mouth can also reflect and influence the systemic health of an individual. Understanding this ecology in dogs may help us to better identify and manage, or even prevent, both oral and systemic disease.

Study participant contributions have a huge impact on advancing aging research

Abigail was very excited to be a part of this research study and to learn a little more about her dog. Mazel didn’t have much to say about the results, but he did enjoy the treat that came with the test kit. Both Abigail and Mazel, along with all the other XTD participants, have made a significant contribution to our understanding of dog aging and our efforts to find better ways to measure aging and to predict and prevent age-related health problems.

At Loyal, we’re continuing to find ways to understand the connection between your dog’s health and aging and its impact on lifespan. We look forward to continuing to 

 that contributes to the future of health and longevity in dogs.

 Microbiota populations in supragingival plaque, subgingival plaque, and saliva habitats of adult dogs. 

https://doi.org/10.1186/s42523-021-00100-9

How old is your dog, really? Predicting age through methylation

We know biological samples can tell us about our dog’s health and breed ancestry, but is the saliva in your dog’s mouth enough to tell us your dog’s age and birthday? The answer is, in some ways, yes.



In Loyal’s <a href="https://blog-admin.loyalfordogs.com/introducing-x-thousand-dogs/">X-Thousand Dogs study</a>—XTD for short—we collected saliva samples from roughly 1,600 dogs of 187 different breeds in 48 US states and health information from their science-loving humans, including a dog named Mazel and his pet parent Abigail. One aspect of this project was measuring DNA methylation and determining a methylation age—a measure of the impact of lifestyle, diet and environment on a dog’s health and longevity.



This is important in several ways. For dogs that were adopted as adults and who have unknown birthdays, determining methylation age might give us a more accurate estimate of chronological age, and help us make choices about preventative healthcare. And someday, with further research, methylation age might help us not only measure the impact of lifestyle and environment of healthspan and lifespan but guide us in making healthier lifestyle and nutritional choices for our dogs. For all dogs, using information directly from a dog’s biology allows you to use snippets of insights over time to evaluate the impact of your dog’s lifestyle and environment on their health and aging.



<h2 class="wp-block-heading" id="mazel-is-a-study-participant-with-an-unknown-age">Mazel is a study participant with an unknown age</h2>



Who is Mazel? Mazel is a brilliant and energetic 10 lb. mixed breed dog with a long back, who resembles a terrier. He was adopted from a shelter in July 2010 as a young adult, but his true age and birthday is unknown. Mazel loves hiking in the hills and exploring, but he’s slowing down and not chasing rabbits anymore.&nbsp;



Abigail, Mazel’s pet parent, describes him at his current age as “sometimes a little arthritic.” She says, “He’s one of those dogs who is longer than he is tall, and he will throw out his back sometimes. That limits him.”



He seemed pretty young, but no one knew his age for certain. Like most dogs with unknown backgrounds, guesses from friends and family—and even from the vet—might all be different. Since the risk of health problems in dogs grows with age, it would be helpful to have a more accurate way to estimate how old dogs like Mazel really are.



<h2 class="wp-block-heading" id="x-thousand-dogs-builds-our-understanding-of-aging-through-epigenetics-and-methylation">X-Thousand Dogs builds our understanding of aging through epigenetics and methylation</h2>



One possible way of doing this is through <a href="https://loyalfordogs.com/x-thousand/epigenetics/">epigenetics</a>. The passage of time and environmental factors change the structure of our dogs’ DNA in ways that influence how their genes work. One such change is <a href="https://blog-admin.loyalfordogs.com/what-is-dna-methylation-and-how-does-it-help-us-understand-longevity/">methylation, the process where methyl groups are added to DNA </a>(as in the animation below).&nbsp;



<figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="640" height="602" src="http://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/DNA-methylation.gif" alt="An animation captioned: DNA Methylation. DNA methylation changes when a methyl group is added or removed to CpG sites. These changes allow us to observe the impact of lifestyle and the environment on dogs as they age. Below the caption is an illustration of a dark blue DNA strand with one nucleotide highlighting red. A box shows a zoomed in version of the nucleotide as a cytosine that is adding and taking away a methyl group. Below this animation is the DNA sequence -AAATACACACCCGAGAA-" class="wp-image-646"/><figcaption>DNA methylation changes when a methyl group is added or removed to CpG sites. These changes allow us to observe the impact of lifestyle and the environment on dogs as they age</figcaption></figure>



Methylation age is closely related to chronological age,and both increase steadily with time. Unlike chronological age, which depends only on time, methylation age reflects the impact of environment, diet, and many other factors on a dog’s DNA. This is why the methylation age and chronological age are usually different for any individual dog. In our XTD study results, we call methylation age the estimated age.



The XTD study was able to show that methylation age can predict chronological age in dogs. Using the largest methylation dataset in dogs to date, we built on previous research to confirm that changes in DNA over time can tell us the chronological age of dogs when we don’t know their date of birth.



<h2 class="wp-block-heading" id="how-does-age-prediction-work">How does age prediction work?</h2>



Based on information from the shelter, Abigail estimates that Mazel was born in August 2009, but she’d always suspected he was older. When she swabbed Mazel earlier this year for XTD, Mazel’s methylation age was 9 months younger than his reported age. The model suggests Mazel’s age is closer to 12 years and 3 months. Rather than older, Mazel was actually younger than the shelter and Abigail expected.



<figure class="wp-block-image size-large is-resized"><img loading="lazy" decoding="async" src="http://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39-1024x598.png" alt="Mazel's age prediction results on a graph, showing a linear dark blue line for all dogs (represented by smaller, lighter blue dots). The graph shows that Mazel's Predicted age through methylation was slightly below 12 years old (closer to 11 years old), and his Reported age was a little over 12 years old. " class="wp-image-647" width="1024" height="598" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39-1024x598.png 1024w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39-300x175.png 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39-768x449.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39-1536x897.png 1536w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/image-39.png 1678w" sizes="(max-width: 1024px) 100vw, 1024px" /><figcaption>Mazel’s age prediction results from X-Thousand Dogs—you can see his estimated methylation age on the vertical axis and reported age from his pet parent Abigail on the horizontal axis</figcaption></figure>



While it’s useful to know how old a dog is more precisely than just a guess based on how he or she looks, chronological age isn’t a perfect predictor of health status. Age affects every dog differently. Just as there are people running marathons in their 80s while others experience serious age-related health problems much younger, some dogs are healthier and stronger than others at the same age.



Beyond chronological age, it would be useful for vets and dog owners to have a reliable measure of age, how much age has affected a particular dog, and what their risk of age-related health problems truly is.



<h2 class="wp-block-heading" id="what-does-methylation-age-prediction-mean-for-my-dog-s-health">What does methylation age prediction mean for my dog’s health?</h2>



It’s possible that methylation age may reflect environmental factors and their impact on health status better than the length of time a dog has lived. Because methylation age is influenced by environmental and lifestyle factors, not just time, it could tell us more about the health status of individual dogs than their chronological age does. This measure of age through methylation could guide us in decisions about medical tests and treatments, diet, activity levels, and other factors that might extend <a href="https://blog-admin.loyalfordogs.com/healthspan-the-healthy-prime-of-life/">healthspan</a> and lifespan for our dogs.&nbsp;



Methylation will likely be an important component of measuring aging, and in adding to our understanding of this process in dogs, the XTD study has opened up more avenues of research for exploration into early cancer detection and environmental factors that impact DNA methylation and aging.



<h2 class="wp-block-heading" id="our-x-thousand-dogs-study-explored-other-health-related-factors-such-as-the-oral-microbiome">Our X-Thousand Dogs study explored other health-related factors, such as the oral microbiome</h2>



In addition to looking at methylation, the saliva samples we collected in the XTD study allowed us to analyze the oral microbiome of participants—the population of bacteria that live in the mouth. These bacteria can perform important roles in promoting health, but imbalances in the oral ecosystem can also increase the risk of disease. For example, Desulfomicrobium orale (D. orale) is linked to lower quality oral health (<a href="https://animalmicrobiome.biomedcentral.com/articles/10.1186/s42523-021-00100-9">Oba 2021</a>).&nbsp;



The population of bacteria in the mouth can also reflect and influence the systemic health of an individual. Understanding this ecology in dogs may help us to better identify and manage, or even prevent, both oral and systemic disease.



<h2 class="wp-block-heading" id="study-participant-contributions-have-a-huge-impact-on-advancing-aging-research">Study participant contributions have a huge impact on advancing aging research</h2>



Abigail was very excited to be a part of this research study and to learn a little more about her dog. Mazel didn’t have much to say about the results, but he did enjoy the treat that came with the test kit. Both Abigail and Mazel, along with all the other XTD participants, have made a significant contribution to our understanding of dog aging and our efforts to find better ways to measure aging and to predict and prevent age-related health problems.



At Loyal, we’re continuing to find ways to understand the connection between your dog’s health and aging and its impact on lifespan. We look forward to continuing to <a href="https://www.axios.com/2022/11/30/aging-humans-dog-lifespan-methylation" data-type="URL" data-id="https://www.axios.com/2022/11/30/aging-humans-dog-lifespan-methylation">share our research</a> that contributes to the future of health and longevity in dogs.



<figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="519" height="519" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/IMG_9697.jpg" alt="" class="wp-image-651" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/IMG_9697.jpg 519w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/IMG_9697-300x300.jpg 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/11/IMG_9697-150x150.jpg 150w" sizes="(max-width: 519px) 100vw, 519px" /><figcaption>Mazel at the beach</figcaption></figure>



<h2 class="wp-block-heading" id="sources">Sources</h2>



Oba, P.M., Carroll, M.Q., Alexander, C. et al. Microbiota populations in supragingival plaque, subgingival plaque, and saliva habitats of adult dogs. anim microbiome 3, 38 (2021). <a href="https://doi.org/10.1186/s42523-021-00100-9" rel="nofollow">https://doi.org/10.1186/s42523-021-00100-9</a>

Dogs come in an astounding range of shapes and sizes. The smallest breeds, like the Chihuahua and Yorkshire Terrier, have a maximum size of about 6-7 pounds, with many individuals weighing less than this. The largest breeds, such as some varieties of mastiffs, can weigh over 150 pounds even when not overweight. 

This variety in size is greater than that of any other species. Dogs vary so much in size and appearance because of  intensive selective breeding by humans. The genetics of body mass is complex, and an individual’s adult size is determined by combinations of many genes. However, scientists have identified a small number of genes which account for almost half of the variation in body size between dog breeds. The general effect of selective breeding on these genes has been to make dogs smaller than their wolf ancestors.

Dogs breeds vary in more than just body size

These genetic changes don’t only affect body size. Dog breeds differ in many other ways, from body shape and color to temperament and even 

 and lifespan. The net effect of the many genetic changes that distinguish large and small breeds is that the smaller breeds tend to live longer than large and giant breeds. There is a direct, or linear, relationship between size and lifespan, so the larger a breed is, the shorter the average longevity of dogs in that breed.

These differences in lifespan can be very large. Some of the biggest breeds, such as English Mastiffs and Bullmastiffs, and Great Danes live only an average of 7-8 years. In contrast, the smallest breeds, such as the Chihuahua, Miniature Poodle, and Yorkshire Terrier, have an average lifespan longer than 12 years and commonly live well into their teens, almost twice as long as much larger breeds.

Genetics also influence health in aging dogs

In addition to overall differences in lifespan, large and small breeds tend to experience somewhat different age-related health problems, those there is much overlap. Large breeds, for example, are more likely to suffer from musculoskeletal disorders, such as arthritis. Cancer also tends to be a more common cause of death in larger breeds. Smaller breeds, on the other hand, are more likely to experience diseases of the nervous system or metabolic disorders, such as glandular diseases and kidney failure.

It is not completely clear why large dog breeds have shorter lifespan than small dog breeds. One possibility is that they may age faster, accumulating physiologic abnormalities and health problems sooner than smaller dogs. Alternatively, they may experience the same overall health impacts of aging as smaller breeds but be less able to cope with and survive these. Research and debate is ongoing to decide between these possible explanations.

Figure 1. Lifespan negatively scales with adult body mass in male and female dogs

Loyal is studying size and its impact on aging

It is clear, however, that body size and growth rate are key factors, and this gives us hope that we could extend the lifespan and healthspan of large dogs by targeting mechanisms associated with these. We understand the genetic differences between small and large breeds, and we know a lot about the effect of these differences on growth rate and metabolism. Loyal is actively investigating therapies to target possible mechanisms underlying the shortened lifespan of large breeds, and we are planning clinical trials to test these in the near future

While owners can’t change the genetics of our dogs, there are many things we can do to give our pups the longest, healthiest life possible whatever their size. Keeping our dogs at a healthy weight, providing regular 

, and keeping up with regular preventative veterinary care can all help maintain good health and keep our canine companions happy and healthy.

Colin Selman, Daniel H. Nussey, Pat Monaghan, Aging: It’s a Dog’s Life, Current Biology, Volume 23, Issue 10, 2013, Pages R451-R453.

Fan R, Olbricht G, Baker X, Hou C. Birth mass is the key to understanding the negative correlation between lifespan and body size in dogs. Aging (Albany NY). 2016 Dec 8;8(12):3209-3222. 

Galis, F., Van Der Sluijs, I., Van Dooren, T. J. M., Metz, J. A. J., & Nussbaumer, M. (2007). 

large dogs die young? Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 308B(2), 119–126

Kraus, C., Pavard, S., & Promislow, D. E. L. (2013). The Size–Life Span Trade-Off Decomposed: Why Large Dogs Die Young. The American Naturalist, 181(4), 492–505

Rimbault M, Beale HC, Schoenebeck JJ, Hoopes BC, Allen JJ, Kilroy-Glynn P, Wayne RK, Sutter NB, Ostrander EA. Derived variants at six genes explain nearly half of size reduction in dog breeds. Genome Res. 2013 Dec;23(12):1985-95. doi: 10.1101/gr.157339.113. Epub 2013 Sep 11. PMID: 24026177; PMCID: PMC3847769.

Why do big dogs have unusually short lifespans compared to small dogs?

Dogs come in an astounding range of shapes and sizes. The smallest breeds, like the Chihuahua and Yorkshire Terrier, have a maximum size of about 6-7 pounds, with many individuals weighing less than this. The largest breeds, such as some varieties of mastiffs, can weigh over 150 pounds even when not overweight.&nbsp;



This variety in size is greater than that of any other species. Dogs vary so much in size and appearance because of&nbsp; intensive selective breeding by humans. The genetics of body mass is complex, and an individual’s adult size is determined by combinations of many genes. However, scientists have identified a small number of genes which account for almost half of the variation in body size between dog breeds. The general effect of selective breeding on these genes has been to make dogs smaller than their wolf ancestors.



<figure class="wp-block-image size-large is-resized"><img loading="lazy" decoding="async" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1-1024x576.png" alt="" class="wp-image-415" width="1024" height="576" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1-1024x576.png 1024w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1-300x169.png 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1-768x432.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1-1536x864.png 1536w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-1.png 1920w" sizes="(max-width: 1024px) 100vw, 1024px" /><figcaption>Based on Figure 1. Body size and lifespan in dogs in <a href="https://www.cell.com/current-biology/pdf/S0960-9822(13)00413-2.pdf" data-type="URL" data-id="https://www.cell.com/current-biology/pdf/S0960-9822(13)00413-2.pdf">Selman et al (2013)</a></figcaption></figure>



<h2 class="wp-block-heading" id="dogs-breeds-vary-in-more-than-just-body-size">Dogs breeds vary in more than just body size</h2>



These genetic changes don’t only affect body size. Dog breeds differ in many other ways, from body shape and color to temperament and even <a href="https://blog-admin.loyalfordogs.com/healthspan-the-healthy-prime-of-life/">healthspan</a> and lifespan. The net effect of the many genetic changes that distinguish large and small breeds is that the smaller breeds tend to live longer than large and giant breeds. There is a direct, or linear, relationship between size and lifespan, so the larger a breed is, the shorter the average longevity of dogs in that breed.



These differences in lifespan can be very large. Some of the biggest breeds, such as English Mastiffs and Bullmastiffs, and Great Danes live only an average of 7-8 years. In contrast, the smallest breeds, such as the Chihuahua, Miniature Poodle, and Yorkshire Terrier, have an average lifespan longer than 12 years and commonly live well into their teens, almost twice as long as much larger breeds.



<h2 class="wp-block-heading" id="genetics-also-influence-health-in-aging-dogs"> Genetics also influence health in aging dogs</h2>



In addition to overall differences in lifespan, large and small breeds tend to experience somewhat different age-related health problems, those there is much overlap. Large breeds, for example, are more likely to suffer from musculoskeletal disorders, such as arthritis. Cancer also tends to be a more common cause of death in larger breeds. Smaller breeds, on the other hand, are more likely to experience diseases of the nervous system or metabolic disorders, such as glandular diseases and kidney failure.



It is not completely clear why large dog breeds have shorter lifespan than small dog breeds. One possibility is that they may age faster, accumulating physiologic abnormalities and health problems sooner than smaller dogs. Alternatively, they may experience the same overall health impacts of aging as smaller breeds but be less able to cope with and survive these. Research and debate is ongoing to decide between these possible explanations.



<figure class="wp-block-image size-large is-resized"><img loading="lazy" decoding="async" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2-1024x576.png" alt="" class="wp-image-416" width="1022" height="575" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2-1024x576.png 1024w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2-300x169.png 300w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2-768x432.png 768w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2-1536x864.png 1536w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/09/Big-vs-small-2.png 1920w" sizes="(max-width: 1022px) 100vw, 1022px" /><figcaption>Based on Figure 1. Lifespan negatively scales with adult body mass in male and female dogs in <a href="https://www.aging-us.com/article/101081/text" data-type="URL" data-id="https://www.aging-us.com/article/101081/text">Fan et al (2016)</a></figcaption></figure>



<h2 class="wp-block-heading" id="loyal-is-studying-size-and-its-impact-on-aging">Loyal is studying size and its impact on aging</h2>



It is clear, however, that body size and growth rate are key factors, and this gives us hope that we could extend the lifespan and healthspan of large dogs by targeting mechanisms associated with these. We understand the genetic differences between small and large breeds, and we know a lot about the effect of these differences on growth rate and metabolism. Loyal is actively investigating therapies to target possible mechanisms underlying the shortened lifespan of large breeds, and we are planning clinical trials to test these in the near future



While owners can’t change the genetics of our dogs, there are many things we can do to give our pups the longest, healthiest life possible whatever their size. Keeping our dogs at a healthy weight, providing regular <a href="https://blog-admin.loyalfordogs.com/dog-enrichment-activities-healthy-brains-and-happy-dogs/">exercise and behavioral enrichment</a>, and keeping up with regular preventative veterinary care can all help maintain good health and keep our canine companions happy and healthy.



Sources



Colin Selman, Daniel&nbsp;H. Nussey, Pat Monaghan, Aging: It’s a Dog’s Life, Current Biology, Volume 23, Issue 10, 2013, Pages R451-R453.



Fan R, Olbricht G, Baker X, Hou C. Birth mass is the key to understanding the negative correlation between lifespan and body size in dogs. Aging (Albany NY). 2016 Dec 8;8(12):3209-3222.&nbsp;



Galis, F., Van Der Sluijs, I., Van Dooren, T. J. M., Metz, J. A. J., &amp; Nussbaumer, M. (2007).&nbsp;Do large dogs die young? Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 308B(2), 119–126



Kraus, C., Pavard, S., &amp; Promislow, D. E. L. (2013).&nbsp;The Size–Life Span Trade-Off Decomposed: Why Large Dogs Die Young. The American Naturalist, 181(4), 492–505.



Rimbault M, Beale HC, Schoenebeck JJ, Hoopes BC, Allen JJ, Kilroy-Glynn P, Wayne RK, Sutter NB, Ostrander EA. Derived variants at six genes explain nearly half of size reduction in dog breeds. Genome Res. 2013 Dec;23(12):1985-95. doi: 10.1101/gr.157339.113. Epub 2013 Sep 11. PMID: 24026177; PMCID: PMC3847769.

Ellen Ratcliff, DVM

Veterinarian pals, listen, I’ve been there. For the better part of two decades, I was a mixed animal practitioner working 80 hour weeks, on call 50% of my life, almost never (

) getting a day off. I was stressed out, overstretched, weary, and just trying to keep my head above water. At the same time I was also bored, fighting stagnancy, and wondering if this was my life from there on out. 

Enter a close veterinary friend who was working in-industry and trying to get me to run clinical studies in my practice. In spite of not feeling like I could add a single new thing to my to do list, and admittedly at least partly due to my inability to say no (

figuring when my head popped off at least I would get some rest in the hospital

That decision changed my practice life for the better, and just happened to also lead me in a new career direction I would have never even otherwise known about. While I am not suggesting everyone pursue a new career, I definitely think practicing veterinarians should consider some of the intangible reasons why participating in clinical trials just might be a good move. Yes, even you (

It can sometimes feel like the day-to-day grind of veterinary medicine is so far removed from your scientist side that you can’t even see it from there with binoculars. Yeah, we have microscopes and fecal samples and ELISA tests. But DOING science can seem like something from our college days. I started being an investigator in research, y’all – something I previously thought was only for academics. I can’t tell you how nice it was to be recognized as a scientist again. Animal health companies need your scientist brain and it makes a gal feel sharp to get to use it.

2. Be a part of something bigger than yourself.

I like being a member of a club or a group of people trying to do something I couldn’t do alone. This is probably why I’m also a veterinarian in the Army Reserve and why we all felt that inexplicable camaraderie in vet school. But in practice life, the stress of staff and clients can really be barriers to that feeling. When you start doing clinical studies in your practice, you become a small part of the mission of the company doing that research. You meet new people working towards that goal and you become an integral part of the team. 

3. Learn a new skill set and a new language.

Are you a whiz at talking about anal glands, atopy, and otitis while telling a technician what fluid rate to set the DKA dog on and asking the receptionist to tell the rat poison dog’s owner to come pick it up, all with one hand tied behind your back? You might be ready to learn a new competency in veterinary medicine. Doing something unfamiliar and stimulating that requires a cobwebby part of your brain feels like a breath of fresh air. The change in scenery on your appointment schedule can really reinvigorate the practice pro. New skills, novel processes, innovative medical care, unfamiliar ways of thinking about a problem you may or may not have even known existed? Fun! 

4. Gain a whole new appreciation for how approved drugs get onto your clinic shelves! 

Spoiler alert – it’s a wayyyy lengthier and more involved process than most of us have any concept about. Veterinary medicine has so few approved drugs compared to human medicine. It can only benefit our profession to have pharmacy shelves with more approved drugs that are extensively studied, found to be effective, but also safe. This just isn’t possible without practicing veterinarians participating in this process. 

Having an inside glance into Good Clinical Practice (GCP) studies and understanding how high the data quality must be and how our personal integrity and attention to detail as the investigator plays into that – pretty nifty. Also pretty cool is getting to use novel therapeutics before they even make it to the shelves. 

5. Novel revenue stream (ok, admittedly this one is tangible).

Doing clinical research in your clinic just might give you the chance to see fewer patients in an hour while making the same income. Or add a few more patients to your schedule and increase your income. That was certainly the case for me. It ended up being an unexpectedly lucrative venture for me as a clinical investigator and the work was interesting, diverse, engaging in a way that made it feel like I had stumbled upon a secret in veterinary medicine. 

It is a fruitful enough endeavor that many practices hire a veterinarian and support staff just to run clinical studies in their practices. Sometimes trial sponsors even help fund this. It can be a great way to grow a practice in a time when vets are losing constant inflow of revenue from online pharmacies and pandemics. 

This is my legit real world experience doing clinical studies as a busy general practitioner. I’d love to find out if any of you have similar experiences or wildly different involvement in this space. So let’s hear it, veterinary colleagues, anyone ready to hear how to dip their tired feet into this pool? 

Dr. Ellen Ratcliff, DVM, brings 17 years of mixed animal practice experience to Loyal as the Director of Clinical Development. She’s a Veterinary Corps Officer in the United States Army Reserve with a wealth of experience in public health and Military Working Dog care. Ellen previously managed clinical development at KindredBio, an animal pharmaceutical company. Ellen completed her DVM at the University of Missouri. She lives at home with her 3 beloved cats and her dog, Sormeh.

Clinical trials in the real world: One practitioner’s perspective

Veterinarian pals, listen, I’ve been there. For the better part of two decades, I was a mixed animal practitioner working 80 hour weeks, on call 50% of my life, almost never (literally never) getting a day off. I was stressed out, overstretched, weary, and just trying to keep my head above water. At the same time I was also bored, fighting stagnancy, and wondering if this was my life from there on out.&nbsp;



Enter a close veterinary friend who was working in-industry and trying to get me to run clinical studies in my practice. In spite of not feeling like I could add a single new thing to my to do list, and admittedly at least partly due to my inability to say no (sound familiar?), I consented to try it (figuring when my head popped off at least I would get some rest in the hospital).&nbsp;



That decision changed my practice life for the better, and just happened to also lead me in a new career direction I would have never even otherwise known about. While I am not suggesting everyone pursue a new career, I definitely think practicing veterinarians should consider some of the intangible reasons why participating in clinical trials just might be a good move. Yes, even you (especially you!) general practitioners.&nbsp;



1. Remember you’re a scientist!&nbsp;



It can sometimes feel like the day-to-day grind of veterinary medicine is so far removed from your scientist side that you can’t even see it from there with binoculars. Yeah, we have microscopes and fecal samples and ELISA tests. But DOING science can seem like something from our college days. I started being an investigator in research, y’all &#8211; something I previously thought was only for academics. I can’t tell you how nice it was to be recognized as a scientist again. Animal health companies need your scientist brain and it makes a gal feel sharp to get to use it.



2. Be a part of something bigger than yourself.



I like being a member of a club or a group of people trying to do something I couldn’t do alone. This is probably why I’m also a veterinarian in the Army Reserve and why we all felt that inexplicable camaraderie in vet school. But in practice life, the stress of staff and clients can really be barriers to that feeling. When you start doing clinical studies in your practice, you become a small part of the mission of the company doing that research. You meet new people working towards that goal and you become an integral part of the team.&nbsp;



3. Learn a new skill set and a new language.



Are you a whiz at talking about anal glands, atopy, and otitis while telling a technician what fluid rate to set the DKA dog on and asking the receptionist to tell the rat poison dog’s owner to come pick it up, all with one hand tied behind your back? You might be ready to learn a new competency in veterinary medicine. Doing something unfamiliar and stimulating that requires a cobwebby part of your brain feels like a breath of fresh air. The change in scenery on your appointment schedule can really reinvigorate the practice pro. New skills, novel processes, innovative medical care, unfamiliar ways of thinking about a problem you may or may not have even known existed? Fun!&nbsp;



4. Gain a whole new appreciation for how approved drugs get onto your clinic shelves!&nbsp;



Spoiler alert &#8211; it’s a wayyyy lengthier and more involved process than most of us have any concept about. Veterinary medicine has so few approved drugs compared to human medicine. It can only benefit our profession to have pharmacy shelves with more approved drugs that are extensively studied, found to be effective, but also safe. This just isn’t possible without practicing veterinarians participating in this process.&nbsp;



Having an inside glance into Good Clinical Practice (GCP) studies and understanding how high the data quality must be and how our personal integrity and attention to detail as the investigator plays into that &#8211; pretty nifty. Also pretty cool is getting to use novel therapeutics before they even make it to the shelves. Very cutting edge, right?



5. Novel revenue stream (ok, admittedly this one is tangible).



Doing clinical research in your clinic just might give you the chance to see fewer patients in an hour while making the same income. Or add a few more patients to your schedule and increase your income. That was certainly the case for me. It ended up being an unexpectedly lucrative venture for me as a clinical investigator and the work was interesting, diverse, engaging in a way that made it feel like I had stumbled upon a secret in veterinary medicine.&nbsp;



It is a fruitful enough endeavor that many practices hire a veterinarian and support staff just to run clinical studies in their practices. Sometimes trial sponsors even help fund this. It can be a great way to grow a practice in a time when vets are losing constant inflow of revenue from online pharmacies and pandemics.&nbsp;



This is my legit real world experience doing clinical studies as a busy general practitioner. I’d love to find out if any of you have similar experiences or wildly different involvement in this space. So let’s hear it, veterinary colleagues, anyone ready to hear how to dip their tired feet into this pool? <a href="mailto:ellen@loyalfordogs.com">Reach out via email</a> or <a href="https://loyalfordogs.com/for-vets/" data-type="URL" data-id="https://loyalfordogs.com/for-vets/">learn more</a> &#8211; I love to talk clinical trials.



<figure class="wp-block-image size-full"><img loading="lazy" decoding="async" width="686" height="452" src="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/08/dr-ellen-ratcliff-dvm-holding-black-dog-veterinary-medicine-2-1.jpg" alt="" class="wp-image-326" srcset="https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/08/dr-ellen-ratcliff-dvm-holding-black-dog-veterinary-medicine-2-1.jpg 686w, https://blog-admin.loyalfordogs.com/wp-content/uploads/2022/08/dr-ellen-ratcliff-dvm-holding-black-dog-veterinary-medicine-2-1-300x198.jpg 300w" sizes="(max-width: 686px) 100vw, 686px" /><figcaption>Dr. Ellen Ratcliff, DVM, brings 17 years of mixed animal practice experience to Loyal as the Director of Clinical Development. She’s a Veterinary Corps Officer in the United States Army Reserve with a wealth of experience in public health and Military Working Dog care. Ellen previously managed clinical development at KindredBio, an animal pharmaceutical company. Ellen completed her DVM at the University of Missouri. She lives at home with her 3 beloved cats and her dog, Sormeh.</figcaption></figure>

As a veterinarian, my job is to help my patients live the longest, healthiest life possible, and to help my clients choose among different treatment options for their pets. When I consider recommending a medicine for my patients, one of the most important things I need to know is how good the scientific evidence is showing that medicine is safe and effective. A really useful resource to help me determine this is whether or not that treatment has been approved for use in dogs by the FDA.

FDA categories help vets distinguish the evidence available for a product

There are different categories of medicines to choose from, and different degrees of regulatory oversight for each, and this can make understanding the strength of the science behind specific treatments a lot easier. 

In general, vets can choose among medicines in several broad categories:

Some treatments are available “over-the-counter,” meaning they have met the same testing requirements as prescription products, but they can be safely and effectively used without supervision by a veterinarian.

How these categories fulfill the needs of our pets

In general, the strength of the evidence identifying both the benefits and the risks of these treatments is greater the closer to the top of the list they are. For example, it takes a lot more research and data in dogs to achieve FDA approval for a prescription medication to be used in dogs than is required for a human drug used off-label or for a dietary supplement. 

The highest bar for scientific evidence is set by full FDA drug approval. This is a complex process that requires demonstrating to the agency that a drug proposed for use in dogs is safe, for the dogs taking it as well as for the humans around them, and that it is effective, meaning it consistently does what it’s expected to do. Full approval requires showing that a drug can be consistently made to a high standard of quality. 

Of course, no scientific or regulatory process is ever perfect. However, the standard of FDA approval is rigorous, and as a vet I know that an approved prescription drug has been tested extensively and has more scientific evidence to support safety and efficacy than any other category of treatment I could use. 

Conditionally approved prescription drugs

 is a relatively new category which recognizes that for conditions that are serious and have no existing effective treatments, a process that makes new drugs available for vets and dog owners to use sooner is beneficial. 

 explaining conditional approval in more detail

Conditional approval requires nearly all of the same conditions to be met, such as proving safety, manufacturing quality, and so on. The only difference from full approval is the type of proof of effectiveness. Rather than meeting the “substantial evidence” for effectiveness standard, which typically requires a clinical trial in companion dogs, conditional approval requires meeting the standard of a “reasonable expectation of effectiveness” (RXE). This standard can potentially be met with studies that involve fewer dogs and shorter time periods than the clinical trials needed for full approval or with evidence already existing in the scientific literature from studies done in the past. 

 announcing the FDA acceptance of RXE for one of our own products

Many more drugs are approved and available for use in humans than in dogs because the biomedical industry for humans is much larger and better funded than veterinary medicine. The FDA recognizes that many potentially beneficial drugs are available in people, or other species, that will never be put through the approval process for use in dogs due to limitations of time, money, or other factors. Since 1994, the agency has allowed vets to use these drugs under specific conditions, and this is known as “

Extra-label use of drugs approved for humans is one of the most common types of medication used in veterinary medicine. Vets understand that the evidence for safety and effectiveness in our patients is not as strong as it is for approved animal drugs, but these drugs are an indispensable tool in caring for our patients.

As long as we, and our clients, understand the limits of the evidence, we can balance risks, benefits and uncertainty in a rational way and monitor patients appropriately to make sure we are truly helping them.

Dietary supplements are the category with the least oversight and the greatest uncertainty about safety and efficacy. In veterinary medicine, this is not even a formal category. As the FDA explains, “there is no ‘dietary supplement’ regulatory classification for animal food substances and products. They are considered either ‘foods’ or ‘new animal drugs’ depending on the intended use.” 

Essentially, anything that is intended to cure, treat, or prevent disease is considered a drug and should, in principle, go through the full or conditional approval process before being marketed for use in dogs. In practice, though, the FDA does not aggressively enforce this policy.

Why a lack of evidence in supplements matters

As a vet, the importance of this to me is that supplements for pets aren’t required to prove they are safe and effective before, or after, being marketed. Most of these products have never been tested in clinical trials.

There is also no official regulatory monitoring of quality for most dietary supplements. 

, for example, that the labels for many probiotic supplements were inaccurate—often the product didn’t have in it what the label said was in it. Even if a specific supplement might have therapeutic effects, your dog won’t benefit from these if the product you buy doesn’t actually contain the ingredients it’s supposed to have!

I do sometimes recommend dietary supplements if there is some scientific reason to believe they might help and are unlikely to be harmful, but my confidence in these products is much lower than for prescription drugs.

Understanding the levels of regulatory oversight can help vets understand the strength of the scientific evidence and the degree of confidence we can have in the medicines we recommend.

There is always some level of risk in doing anything in medicine, and this has to be balanced against the benefits of what we are considering doing. In a dog who is seriously ill, a medicine that can cure them or greatly relieve their suffering has a lot of potential benefit. The risk of some side effects may well be worth taking in such a case. For a healthy dog in whom we are aiming to prevent illness down the road, we would be a lot less likely to take any significant risks at all with our preventive treatments.

However, as a vet and as a dog owner myself, I can only decide what is best for my patients and my pets if I know what the potential risks and benefits are for the medicines I have available. The levels of regulatory oversight I have described can help a lot in understanding the strength of the scientific evidence and the degree of confidence I can have in the medicines I recommend.

Whenever possible, I will always choose those treatments that have the highest degree of evidence behind them because this gives me the greatest chance of helping the dogs I care for. 

Some veterinary products are regulated by other agencies, such as certain parasite preventatives (EPA) and vaccines (USDA), but FDA is responsible for approving most prescription drugs.

”off- label” is a common term vets use to describe what the FDA more often calls “extra-label” drug use.

Drugs and dietary supplements for dogs: What’s the difference?