Testing Cognitive Decline in Aging Dogs

“Researchers have found that a suite of complementary tests can quantify changes in dogs suspected of suffering from cognitive decline. The approach could not only aid owners in managing their elderly canine’s care, but could also serve as a model for evaluating cognitive decline progression in — and treatments for — humans with Alzheimer’s disease.”


Canine cognitive dysfunction syndrome (CCDS) is similar to Alzheimer’s disease in humans in that cognitive decline is associated with the development of amyloid plaques as well as cortical atrophy, a progressive degeneration of brain tissue. CCDS is also challenging to diagnose. Traditionally, CCDS is diagnosed based on ruling out any obvious physical conditions and an owner’s answers to a questionnaire. But the current method of diagnosing CCDS is problematic because there may be other factors at play that give the appearance of cognitive decline.  Researchers set out to uncover and compile a series of cognitive tests that could help more accurately assess and diagnose (or dismiss) CCDS.

Study overview

Researchers recruited 39 dogs from 15 breeds. All of them were in the senior and geriatric age range, but in good health overall. A dog is considered “senior” if it is in the last 25% of its expected life span based on breed and size, and geriatric beyond that.

The dogs underwent physical and orthopedic exams, as well as lab work that included a blood test that is a marker of neuronal death (dying off of brain tissue). Their owners filled out two commonly used diagnostic questionnaires, and then the dogs participated in a series of cognitive tests designed to assess executive function, memory and attention.

Results overview

The research team found that cognitive and blood test results correlated well with the questionnaire scores, suggesting that a multi-dimensional approach can be used to quantify cognitive decline in aging dogs.


“Being able to diagnose and quantify CCDS in a way that is clinically safe and relevant is a good first step toward being able to work with dogs as a model for Alzheimer’s disease in humans.”

-Dr. Natasha Olby


Journal Reference:  Gilad Fefer, Wojciech K. Panek, Michael Z. Khan, Matthew Singer, Hans Westermeyer, Freya M. Mowat, David M. Murdoch, Beth Case, Natasha J. Olby, Margaret E. Gruen. Use of Cognitive Testing, Questionnaires, and Plasma Biomarkers to Quantify Cognitive Impairment in an Aging Pet Dog Population. Journal of Alzheimer’s Disease, 2022; 1 DOI: 10.3233/JAD-215562