New in dog health: Sniffing out this month’s discoveries in science

Cover Image for New in dog health: Sniffing out this month’s discoveries in science
Brennen McKenzie, MA, MSc, VMD
by Brennen McKenzie, MA, MSc, VMD

Hero image: Erica Andrews, Head of User Research at Loyal

1. Do dogs “see” with their noses? New study shows connections between the brain areas handling smell and vision.

Though dogs are known for their amazing sense of smell, there is still much to learn about how this ability works and how dogs “see” the world through their super sensitive noses. A recently published study, led by Loyal’s own Erica Andrews, adds valuable new insight into the canine sense of smell. 

As in humans, smell in the dog is closely linked to the limbic system and entorhinal cortex, parts of the brain involved in memory and emotion. This suggests that odors might evoke strong feelings or even specific memories in our canine companions. 

The study also showed, for the first time in any species, a connection between smell and the visual areas of the brain. Dogs use smell to locate objects and orient themselves in space, and this new evidence suggests they may form mental maps of their environment partly with smell, in some sense “seeing” with their noses as well as their eyes!

Read more about Erica’s study, which was also covered by Laura Sanders in Science News and watch co-author’s Alexandra Horowitz’s Ted talk on olfactory overview for more information.

This illustration by Erica Andrews shows olfactory white matter pathways of the canine and was featured as the cover image for Vol. 42, Issue 33 of JNeurosci: The Journal of Neuroscience.
This illustration by Erica Andrews shows olfactory white matter pathways of the canine brain as the cover image for Vol. 42, Issue 33 of JNeurosci: The Journal of Neuroscience and within the article.

More about our neuroimaging expert
Erica brings a multidisciplinary approach to problem-solving with 7 years experience in academic neuroimaging studies at King’s College London and Cornell University while building collaborations with Harvard University, John Hopkins, Columbia University, CNIC Barcelona, and Vrije University Brussels amongst others.

She has researched brain structure and function from different species including humans, dogs, cats, horses and tigers and is a member of Women in Data (WiD), a nonprofit dedicated to supporting women in data science and other STEM roles. She is currently Head of User Research at Loyal where she bridges the gap between users, their dogs, data and science. She is accompanied by her two beloved cats Sauerkraut and Sonny Gray.

Erica Andrews’ cats: Sauerkraut and Sonny Gray

2. Can you tell when your dog has done something wrong by their “guilty” look? New research shows that look may not mean what you think

Have you ever come home to find your dog had chewed up a couch cushion, a shoe, or some other forbidden object? Or maybe your supposedly house-trained pup had an accident on an expensive rug? When we discover our dogs have broken our rules for their behavior, we often get the feeling they know they have done something wrong. There’s this “guilty” look in their eyes. 

As a vet, I have long tried in vain to convince owners that this isn’t consistent with how dogs think. They don’t understand rules and consequences in the same way humans do, and that “guilty” look is more a reaction to our displeasure than a sign of any awareness that they have done something wrong. Now I can point to a scientific study clearly demonstrating this.

In this clever experiment, researchers either prevented dogs from eating a treat their owners had told them not to eat, or the scientists let the dogs have the snack. Sometimes they told owners the truth about what the dog had done, and sometimes they didn’t. The end result showed clearly that the “guilty” look from the dogs was purely a reaction to their owners’ belief the dog had broken the rules, not to what the dogs actually did!

Read more about this study, and see more on this story in Science Daily.

3. Older dogs who are hard of hearing may be at greater risk for dementia, just like older humans.

Hearing loss is a common age-related disorder in humans, and one of its most serious consequences is an increase in the risk of dementia. Dogs also experience hearing loss with age, though this can be harder to recognize until the loss is severe. Little research has been done to evaluate the impact of age-associated hearing loss on dogs.

A newly published study tested dogs for hearing loss with special equipment that could classify the severity of the change. The researchers also evaluated quality of life and the presence and severity of cognitive dysfunction, a condition in aged dogs much like dementia in humans. The study showed that hearing loss reduced quality of life and increased the risk of cognitive dysfunction in dogs just as in humans. 

While we don’t yet have hearing aids for dogs, there are many ways owners can help these dogs compensate and maintain mental function and quality of life. Training using visual cues, enrichment activities involving sight, touch and smell, and opportunity for safe, enjoyable physical activity can all help our dogs live rich lives even when their sense of hearing has diminished.

Read more about this study. Find more on this story in Science Daily.

4. Our dogs may be able to catch monkeypox from us. Should we be worried?

Whenever an infectious disease begins circulating among humans, there is always the question of whether our dogs might be affected or might transmit the disease to humans or other dogs. Often, as with COVID-19, there is very little risk. However, a new study suggests that the monkeypox virus can be spread from humans to dogs.

It is still unknown whether an infected dog could spread the virus, and the main source of infection for nearly all humans is close physical contact with other humans. Out of an abundance of caution the Centers for Disease Control and Prevention recommend testing dogs if they are suspected to have monkeypox, based on known contact with an infected person and the typical skin rash or other symptoms. 

The risk to and from our dogs is certainly low, but owners should consult their veterinarian if they have any questions about monkeypox.

Read more about this study. A helpful summary on the Worms & Germs blog by Scott Weese

5. Use of opioids and cannabis by people can put our dogs at risk.

One of the reasons dogs make such a great model of aging in humans is that they share our environment, with all the potential health risk factors it contains. Unfortunately, this sometimes means that our behavior can create health risks for our dogs. A recent study illustrates this by showing that cases of accidental cannabis and opioid poisoning in dogs are associated with rates of use among humans. 

While cannabis exposure is rarely fatal in dogs, it can lead to serious illness and hospitalization. Edibles pose a particular risk because they may contain chocolate or other toxins that are more dangerous to our dogs than the cannabis itself. Opioid poisoning is much more dangerous, and unfortunately the risk of this increases for dogs in areas where rates of opioid prescriptions or illegal use are high.

Read more about this study


  1. Extensive Connections of the Canine Olfactory Pathway Revealed by Tractography and Dissection. Erica F. Andrews, Raluca Pascalau, Alexandra Horowitz, Gillian M. Lawrence, Philippa J. Johnson.  Journal of Neuroscience 11 July 2022, JN-RM-2355-21; DOI: 10.1523/JNEUROSCI.2355-21.2022
  2. Horowitz et al. Disambiguating the ‘guilty look’;: Salient prompts to a familiar dog behaviour. Behavioural Processes, 2009; 81 (3): 447 DOI: 10.1016/j.beproc.2009.03.014
  3. Gilad Fefer, Michael Z. Khan, Wojciech K. Panek, Beth Case, Margaret E. Gruen, Natasha J. Olby. Relationship between hearing, cognitive function, and quality of life in aging companion dogs. Journal of Veterinary Internal Medicine, 2022; DOI: 10.1111/jvim.16510
  4. Seang S. Burrel S. Todesco E. et al. Evidence of human-to-dog transmission of monkeypox virus. Lancet. August, 2022. Online first.
  5. Howard-Azzeh M, Pearl DL, Berke O, O’Sullivan TL (2022) Spatial, temporal, and space-time clusters associated with opioid and cannabis poisoning events in U.S. dogs (2005–2014). PLoS ONE 17(4): e0266883. 

Jumbo, miniature american shepherd whispers in human's ear
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