Dartmouth native leads study to understand dog dementia

Apr 18, 2024

A cure for dementia may be on the horizon — good news for humans and dogs alike.  

As it happens, dementia affects dogs probably as much as it affects humans, according to Veterinarian and Dartmouth native Gregory Pietsch, who is now an assistant professor of veterinary medicine at the University of Alaska Fairbanks. 

Pietsch is the principal investigator for a study that seeks to better understand and diagnose dog dementia, or Canine Cognitive Dysfunction. The study, headed by the University of Alaska Fairbanks, will eventually be testing a new drug, developed by NeuroNascent, Inc., that has the potential to cure dementia in dogs. If successful in dogs, the drug could eventually be used to cure Alzheimer’s disease in humans. 

Pietsch graduated from Dartmouth High School in 1991 and worked with his father and sister at Anchor Animal Hospital, located at 750 State Road, before eventually moving back to Fairbanks, Alaska where he lives today. 

From studies in mice, the drug has been shown to regenerate brain cells, or neurons, that are responsible for transmitting critical information like memories, Pietsch said. 

“We think this could be a great drug for treating this disease in dogs,” he said.

Using an MRI machine, the study will evaluate the brains of dogs diagnosed with dementia. The scans will measure the size of the hippocampus, the part of the brain associated with memory. 

As dementia progresses and kills brain cells, the brain shrinks, Pietsch explained. He expects that MRI scans will confirm this shrinkage in the brains of dogs diagnosed with dementia. 

There is currently no treatment for reversing dementia in either dogs or humans.

“Once you have a damaged or destroyed nerve cell in the brain, it doesn’t come back,” Pietsch said. “Even if you can slow the disease — the damage that is done is done.”

The study is still in its early stages, and Pietsch said it will be a while before they’re ready to test the drug in dogs. For now, the study is focused primarily on finding dogs in the Fairbanks community that show symptoms of mild to moderate dementia. 

One method for diagnosing dogs with dementia is the Canine Dementia Scale or CADES, which assesses the frequency of abnormal behaviors in dogs believed to have dementia. CADES isn’t widely used in veterinary clinics, which may explain why dog dementia is underreported, Pietsch said. 

Aside from anti-anxiety medications and mild sedatives, Pietsch said the options for managing dementia in dogs are limited. MRI scans and CADES evaluations will be used to assess the drug’s effectiveness in treating canine dementia. 

If the drug successfully regenerates brain tissue lost to dementia, then MRI scans will presumably reveal an increase in the size of the dogs’ brains or at least show that their brains aren’t shrinking as quickly, he said. 

Dementia affects dogs in much the same way as it affects people, Pietsch said. Symptoms in dogs include changes in sleep patterns, such as sleeping during the day and becoming more active at night. Humans with dementia experience similar symptoms, referred to as sundowner’s syndrome, in which they become restless and disoriented at night.

Other symptoms in dogs include wandering as if lost, pacing, forgetting commands as well as forgetting house training and having more accidents. 

Often, dogs with dementia are easily startled because they no longer recognize people, pets or objects that were familiar to them. This can result in dogs becoming more irritable and potentially aggressive.

“They’re going to be more reactive to things, more easily startled if they don’t recognize something,” he said. 

Pietsch advises pet owners to be cautious and closely monitor dogs that show symptoms of dementia. This could mean staying away from dog parks or being more careful when introducing the dog to people or children to avoid upsetting the dog. 

Dementia typically goes undiagnosed in dogs because people mistake these behaviors as a natural part of dogs getting older, Pietsch said. It’s the responsibility of pet owners to pay careful attention to behavioral changes in their pets that could indicate dementia, he said. 

“A lot of people just don’t recognize it in their pets,” he said. “They just think they’re getting older.”

A loss of smell is also a symptom of dementia experienced in humans, Pietsch said, so it follows that dogs with dementia may also lose their sense of smell, a severe detriment considering how heavily dogs rely on their sense of smell to navigate their world. 

Smell is as vital to dogs as sight is to humans, Pietsch explained. Olfactory bulbs, the bundles of nerves near the nasal cavities that process smells, are far larger in dogs than in humans. 

“It’s really impressive how much more of their brain is dedicated to smell than us,” he said. “It’s a hugely important sense for them. … They view the world much more through their nose.”

With this in mind, the study may involve testing a dog’s sense of smell, as a decline in a dog’s sense of smell may indicate dementia, he explained. 

Ultimately, Pietsch said he hopes that the study contributes to a better treatment for dogs suffering with dementia. 

“I’ve seen tons of dogs over the year’s suffer from this,” he said. “It’s heartbreaking and it’s frustrating having limited ability to help as a veterinarian.”