Dementia is an age-associated symptom characterized by significant and progressive cognitive decline, impacting every aspect of life. In humans, Alzheimer’s disease accounts for more than 50% of all forms of dementia. It occurs in approximately 10% of people age 65 and over and is the sixth leading cause of death in the United States. Characterized by memory loss, disorientation, anxiety, loss of appetite and reduced social interactions, it is a devastating and tragic disease for everyone involved.
Companion dogs, because of their similar biology and unique relationship to humans, suffer dementia as well. While sharing many similarities to Alzheimer’s in humans, Canine Cognitive Disorder differs in some respects. Alzheimer’s in humans is characterized by the build-up of both amyloid plaques and neurofibrillary tangles. While the plaques accumulate in some disorders in dogs, it is not clear if the relationship between accumulation and Alzheimer’s symptoms is as correlated in dogs as is it is in humans. In addition, dogs do not show the complete formation of the tangles seen in humans with the disease.
Complicating our understanding of dementia in dogs is that it is far more difficult to diagnose based on symptoms alone. Symptoms of Canine Cognitive Disorder include disorientation, decreased energy, loss of appetite and sleep, and reduced social interaction. CCD is diagnosed mainly by eliminating other possible explanations, but many of them can be confused with other disorders in dogs. For example, diabetes, arthritis, kidney problems, infections, or simply loss of vision and/or hearing need to be ruled out before reaching a conclusive diagnosis.
As you might imagine, active research into canine dementia is a relatively new field with insufficient data to draw significant conclusions. As a result, our understanding of aging and age-related cognitive decline in dogs is astonishingly incomplete. A functional decline in cognition occurs in about 14-50% of dogs between the age of 12 and 14, depending on reports, and it is impossible to predict the number of dogs that go undiagnosed. An exhaustive effort for data collection alone would provide a significant contribution to our understanding of age-related dementia in dogs.
What is clear is that Canine Cognitive Disorder is a progressive disease that bears some strong similarities to Alzheimer’s in people. And there is no cure. One of our goals at the Dog Aging Project is to understand the prevalence and causes of age-related diseases, including dementia, in the average family pet. This does not require medication or interventions of any kind. It is simply a matter of data collection on a massive scale. This Longitudinal Study of Aging will not only identify factors that influence disease, but it will help us inform owners and veterinarians about preventative measures to keep our canine companions healthy and disease free as long as possible. We are in the process of organizing this study and are looking for both volunteers and donations. Please join us if you are able.
by Tammi Kaeberlein
photo by Alicia Romano