Is your dog developing dementia? - study

A slower walking speed in elderly dogs has an association with dementia risk, just as it does in their aging human companions, according to a new study. 

The research on canines, published this week in peer-reviewed journal Frontiers in Veterinary Science, found that measuring gait speed among geriatric dogs could serve as an easy and reliable way to monitor their health and document resulting declines in brain ability as they age. 

“Walking speed in people is strongly associated with cognitive decline,” says Natasha Olby an author of the study from North Carolina State University. “We hypothesized that the same might be true in dogs.”

The researchers examined off-leash gait speed among 46 adults and 49 senior dogs.

The team considered the adult dogs the healthy control group, and measured just their gait speed. Meanwhile, the senior dogs underwent further cognitive testing requiring their owners to fill out a cognitive assessment questionnaire called CADES. A higher CADES score meant more significant cognitive decline.

Each dog's gait speed was measured by being walked over a five-meter distance on a leash with a human. Next they were offered a treat the same distance away while being called for them to retrieve it off their leash.

Olby explained this was a challenge because "dogs tend to match the speed of their handler when on leash, so we measured both on and off leash to see which was the most useful measure."

“Additionally, we are always concerned that body size and limb length will affect gait speed – but if you see a chihuahua and a great dane walking together off leash, the shorter one isn’t always behind the other,” Olby continued. “We found that on leash, size does correlate with gait speed, but off leash it doesn’t make a difference. Capturing gait speed off leash lets us see the effects of both physical ability and food motivation.”

The research team concluded that among the senior dogs, size didn’t matter regarding speed. Dogs in the last 25 percent of their expected lifespan moved more slowly than adult dogs, regardless of their relative sizes.

“Just as in humans, our walking speed is pretty stable through most of our lives, then it declines as we enter the last quarter or so of our lifespan,” Olby said. 

Notably, older dogs who moved more slowly had more significant levels of cognitive decline based on the questionnaires owners filled out. Furthermore, they did worse on the cognitive testing.

Other similarities between dogs and humans with dementia

In another study by Olby, published in May, it was found that dogs may have the same disruptive sleep patterns as humans when suffering from an Alzheimer's or dementia diagnosis.

An early indicator of Alzheimer's disease is a disruption in sleep patterns. Many sleep-related issues, from daytime sleepiness, staying awake longer, to waking up in the middle of the night, are believed to stem from damage to sleep-regulated areas of the brain. However, these patterns are not based solely on the human brain, but can also be identified in dogs. 

The research was also published in Frontiers in Veterinary Science.