Senior dogs slow down. Everyone knows that. The graying muzzle, the creaky joints, the nap that used to last an hour now lasting all afternoon—most owners chalk it up to age and leave it at that. A new study out of North Carolina State University suggests paying closer attention.

Published in Frontiers in Veterinary Science, the research found that a shortening of front leg stride length could serve as an early physical indicator of canine cognitive dysfunction syndrome (CDS), the dog equivalent of Alzheimer’s disease.

Researchers analyzed 88 elderly dogs over several years, conducting physical, neurological, and orthopedic assessments every 6 months. The finding that stood out was that shorter front-leg strides corresponded to lower cognitive test scores—and the effect held even after accounting for age and chronic conditions. 

“Here we show that the length of front leg stride taken by dogs decreases with age, but even more importantly, decreases with a cognitive impairment,” said veterinary neurologist Natasha Olby, one of the study’s lead researchers. “The effect of cognitive decline is larger than the effect of age by itself.”

Your Senior Dog’s Shorter Stride Could Signal More Than Old Age

The front legs specifically matter because of how the brain controls them. The hind legs handle forward propulsion. The front legs manage direction changes and braking, functions that draw on higher-level brain processing. “The cerebral cortex integrates more sensory information into the neuronal circuits which produce steps in the front legs,” Olby explained, “and so loss of high-level sensorimotor integration affects them differently.” In other words, a dog’s front stride is a window into what’s happening neurologically, not just physically.

CDS is estimated to affect up to 60% of dogs over the age of 11, according to ScienceAlert, and it remains significantly underdiagnosed due to the lack of objective, reliable diagnostic tools. The condition shares biological hallmarks with Alzheimer’s—including beta-amyloid accumulation and neuroinflammation—which is part of why researchers believe studying it in dogs could yield insights applicable to human medicine. People with advanced Alzheimer’s also show reduced walking speed and shorter stride length, making the parallel more than coincidental.

For dog owners, the action is simple. A shortened front-leg stride has other possible explanations, including arthritis and neck issues, both of which are treatable—so a vet visit is the right move regardless.

“If owners notice that their dog’s front leg stride is becoming shorter, they should visit their vet,” Olby said. No special equipment is needed to spot the change, just consistent attention to how a dog moves day to day, which is something most owners are already doing without realizing it counts for anything.