This month in dog health: October 2022

Cover Image for This month in dog health: October 2022
Brennen McKenzie, MA, MSc, VMD
by Brennen McKenzie, MA, MSc, VMD

1. Yes, your dog knows when you’re stressed; they can smell it!

Dog owners know that our canine companions are exquisitely sensitive to our emotions, and research has shown dogs can judge how familiar humans and even strangers are feeling based on facial expression and smell. A recent study found that companion dogs can recognize even very subtle changes in a human’s scent that relate to their mood. 

The humans in this study were stressed by being asked to do a challenging math problem, and the impact on their stress level was measured by heart rate, blood pressure, and a series of survey questions. Samples of the humans’ breath and saliva were taken before and after this harrowing experience.

The dogs in the study were trained to pick out the sample taken after the stressful experience. They could correctly tell the before and after samples apart over 90% of the time!  

You can read the full study here with pictures of the sniffing dogs in-action. 

2. More amazing canine noses: can dogs smell COVID-19?

Another example of the awesome olfactory abilities of our canine friends is their apparent ability to detect COVID-19 infection in humans by smell. A recent study found dogs could correctly identify samples as coming from COVID positive or negative individuals more than 95% of the time. This is similar to the accuracy seen in previous studies, and it compares pretty well with home antigen tests.

Some detection dogs are more accurate than others, and no dog is perfect. Also, training a dog to sniff out COVID-19 is time-consuming and expensive, so dogs won’t be replacing those home antigen tests any time soon. But this is another great example of how amazing the canine nose really is.

See the full publication to learn how labradors Xena, Quake, Quimby, and Nugget—among other great names––accomplished this.

3. Laser therapy for skin disease in dogs?

Low-level laser therapy (LLLT) is high-tech treatment that is growing in popularity in veterinary medicine. Overall, the research evidence for benefits from LLLT is encouraging but pretty limited. 

A recent review of studies using LLLT for treatment of skin disease in dogs found that it might help for some kinds of infection, but overall there wasn’t much evidence to support other uses. So far, LLLT seems pretty safe, but we don’t yet know how much it truly helps our canine patients.

Learn more about this potential treatment and supporting literature.

4. Hearing loss—a common and important problem in aging dogs

It is well-known that hearing loss is a common feature of aging in humans, particularly in the higher frequencies that can impair our ability to understand speech. A recent study has confirmed what vets and pet owners have long suspected-dogs experience much the same kind of hearing loss with age. 

This study also shows that this loss of hearing can reduce quality of life and increase the risk of age-related changes in behavior and cognitive function. While we aren’t quite ready to start using hearing aids in dogs, this research suggests we can improve function and quality of life by accommodating age-related changes in hearing. 

Using more visual cues for commands and ensuring that our dogs get plenty of stimulation and enrichment to keep them happy and keep their brains functioning well can combat the impact of hearing loss in our senior dogs.

Read more about the impact of hearing loss on aging dogs.

5. Human activity levels affect our dogs’ activity levels and weight

Just as in people, one of the most significant health hazards dogs face is being overweight. Proper weight management can improve health and quality of life and can help dogs to live longer. 

Since we control the key factors that determine our dogs’ weight, including their diet and exercise, how dog owners see their dogs’ weight status, and how they approach their own diet and exercise, are important factors for vets and canine health advocates to understand. 

A recent study surveyed dog owners in the U.S. and several European countries about these issues. One interesting finding was that people with the lowest levels of exercise (engaging in vigorous activity 2 days a week or less) also reported that their dogs exercised less than those of people who were more active. Both the respondents in this survey and other studies show us that owning dogs makes us more active. It turns out that the how active we are also affects the exercise our dogs get, which influences their healthspan and lifespan.

Figure 1 from Banton et al (2022) compares time spent performing vigorous activity of respondents to the vigorous exercise of their dogs

This study also found that almost 87% of owners thought their dogs were an ideal weight. Since research shows that between 20% and 70% of dogs are actually overweight, most of us are probably not great judges of our dogs’ weight! 

This research is important because our perceptions and behavior are critical factors determining the health and wellbeing of our dogs.

The full study reveals more insights into the weight management of our canine companions, including which breeds are more likely affected by obesity and attitudes that can affect your dog’s weight.


  1. Wilson C, Campbell K, Petzel Z, Reeve C (2022) Dogs can discriminate between human baseline and psychological stress condition odours. PLoS ONE 17(9): e0274143.
  2. Chaber AL, Hazel S, Matthews B, Withers A, Alvergnat G, Grandjean D, Caraguel C. Evaluation of canine detection of COVID-19 infected individuals under controlled settings. Transbound Emerg Dis. 2022 Sep;69(5):e1951-e1958. 
  3. Perego, R.; Mazzeo, M.; Spada, E.; Proverbio, D. Critically Appraised Topic on Low-Level Laser Therapy (LLLT) in Dogs: An Advisable Treatment for Skin Diseases? Vet. Sci. 2022, 9, 505.
  4. Fefer G, Khan MZ, Panek WK, Case B, Gruen ME, Olby NJ. Relationship between hearing, cognitive function, and quality of life in aging companion dogs. J Vet Intern Med. 2022 Sep;36(5):1708-1718.
  5. Banton S, von Massow M, Pezzali JG, Verbrugghe A, Shoveller AK (2022) Jog with your dog: Dog owner exercise routines predict dog exercise routines and perception of ideal body weight. PLoS ONE 17(8): e0272299.  
Jumbo, miniature american shepherd whispers in human's ear
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