Dog Dementia Now Has Its First Standardized Diagnostic Guidelines: The Signs to Watch From Age 7

Dog dementia, which vets call canine cognitive dysfunction syndrome (CCDS), now has its first standardized guidelines for diagnosis and monitoring. A working group of 12 experts, supported in part by the AKC Canine Health Foundation, published them in the Journal of the American Veterinary Medical Association in December 2025, and in October 2026 they were named one of eight semifinalists for the AKC Canine Health Foundation’s Discovery of the Year. What changes for you: a clearer list of signs, a suggested age to start screening, and a shared way for vets to follow the disease over time.

The guidelines define CCDS as a “chronic, progressive, and age-associated neurodegenerative syndrome.” Their lead author, Natasha Olby of NC State, describes them as “a starting point that can be built upon over time.” That modesty is worth keeping in mind: this is a shared framework, not a new blood test.

The signs: DISHAA

The guidelines group the signs into six areas, known by the acronym DISHAA:

• Disorientation: seeming confused in surroundings the dog knows well.
• Social interaction changes: a change in how the dog relates to people or other pets.
• Sleep disruption: a change in the sleep-wake pattern.
• House soiling: accidents in a dog that was house-trained.
• Learning, memory and activity changes: losing what the dog had learned, or a change in how active it is.
• Anxiety: new or increased anxiety.

These are the six areas the guidelines define; how they show up varies from dog to dog. My older guide to dog dementia signs goes through each one in more depth, and the free dementia signs checklist helps you keep track.

When to start watching

The suggested schedule, as reported by dvm360:

• From about age 7: routine behavior questions at senior visits.
• If problems are reported: a formal CCDS scale, repeated every 6 months.
• From age 10: the scale every 6 months as a matter of routine.

How common is it? Studies cited by the University of Veterinary Medicine Hannover, one of the authors’ institutions, suggest about 1 in 3 dogs are affected by age 12 and about 1 in 2 by age 15.

How the diagnosis works

The guidelines set two levels of certainty and three stages of severity: mild, progressive and severe.

• Level 1: a history of worsening DISHAA signs, with other causes ruled out by a physical exam, an orthopedic and a neurologic exam, and lab work, and with the signs still present after other conditions are treated.
• Level 2: adds a brain MRI showing shrinkage of the brain’s outer layer (the cortex), with normal spinal fluid.

Ruling other causes out matters more than it sounds. In a small 2026 study of senior dogs in Turkey, every dog scored above a chronic-pain threshold, and the authors warned that poor scores on thinking tests “may reflect pain-related deficits in motivation, attention, or physical comfort.” An arthritic dog that won’t get up to greet you is not necessarily a confused one.

About the fecal transplant pilot

In June 2026, JAVMA published a pilot titled “Fecal microbiota transplantation shows promise in slowing or reducing cognitive impairment in aging dogs.” Eleven dogs with suspected dementia took oral fecal transplant capsules (donor stool) every 12 hours for 90 days, and owners scored them on the DISHAA scale.

Here’s what’s under the title: only 6 dogs had complete 90-day results. Four improved and two got worse. One dog was withdrawn for stomach upset. There was no control group, the scores came from owners, and three of the five authors list a microbiome company, Animal Biome, as their affiliation. The authors themselves suggest it only “as adjunct therapy” and call for a larger, longer study. That’s a hypothesis worth testing, not a treatment to buy.

What this means for you

If your dog is 7 or older, ask your vet to include behavior and memory questions at senior visits, even if they don’t come up on their own. Write changes down with dates (a senior wellness tracker makes this easy), because “she’s been different lately” is hard to act on and “she’s gotten stuck behind the couch three times this month” is not. Expect your vet to look for pain and other illness first. And if it is dementia, my guide to dog dementia signs and what helps covers comfort and routine, and the AKC Canine Health Foundation keeps an owner hub at akcchf.org/agingdogdementia.