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Dogs Can Have Dementia, Too

Like their owners, many of them face diminished mental capacity in their old age

9:00 AM CST on February 16, 2026

Close-up of a senior black retriever. Credit: Mary Swift / Shutterstock.

Many people who have an older friend or relative are familiar with dementia. With nearly half of Americans older than 55 developing some form of dementia, according to the National Institutes of Health, it’s becoming a salient feature of our aging populations. From memory loss to mood changes and confusion, the symptoms of dementia are unfortunately pervasive. 

Dementia is a sad fact of a dog’s twilight years as well.

Canine cognitive dysfunction syndrome (CCDS) has been diagnosed with increasing frequency in recent years. An international working group of experts from Germany, Canada, Hungary, and the United States came up with the first standardized practices for diagnosis of CCDS, and their new study published in the AMCA Publications describes signs pet owners and veterinarians should watch for in aging dogs.

Laboratory-bred beagles had previously yielded scientific data about the process of cognitive aging in dogs. But the trajectory of mental aging of companion dogs in home settings is less well understood. To date, veterinarians have relied on caregiver questionnaires about pet dogs’ behavior. While the responses may raise red flags, there hasn’t been a systematic way to deal with those warning signs.

Read more: “How Animals Understand Death”

“The good news here is that there is increased interest in finding treatments for CCDS,” said study author and North Carolina State University veterinary neurologist Natasha Olby in a press release. “But in order to develop those treatments we must first be sure there’s an agreed upon definition of the condition.” 

In dogs, the neurodegenerative changes that signal dementia include disruptions in sleep, anxiety, loss of house training, altered activity levels, and declines in learning and memory. The researchers created a diagnostic flowchart, based on those symptoms, ranking severity from mild to debilitating. They recommend that senior dogs, like senior humans, get regularly screened, which, for a dog, means starting at about seven years of age. 

Discovery of symptoms by a dog owner or caregiver would trigger a more intensive follow-up with a detailed CCDS questionnaire. While the American Academy of Neurology recommends annual screening for memory problems from age 65 onward, the study authors recommend screening every six months beginning at age 10 for dogs, as dogs obviously mature and age faster than humans.

The guidelines aren’t the be-all and end-all in standardized CCDS diagnosis, but rather the beginning. “We recognize that this document is just the start of the process,” Olby admitted, “but it was developed as a working live document that can be added to over time as our understanding improves.”

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Lead image: Mary Swift / Shutterstock

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