Dementia in dogs is surprisingly common, but many people don’t realize their dog is suffering from a condition beyond normal aging until the disease is advanced. canine Cognitive Dysfunction Syndrome, or CDS, is considered a neurodegenerative disease of older dogs characterized by various pathological processes that lead to reduced cerebral blood flow and accumulation of free radicals in the brain.
Pet owners have long been frustrated by age-related behavior changes, including house-training problems, apparent memory loss, disorientation, confusion, staring, wandering, getting stuck in corners, sleep disturbances (waking at the wrong time, sleeping unusually deeply, night pacing/anxiety), restlessness, barking, separation anxiety, panting, drooling, obsessive licking, etc.
A recent study at the University of California-Davis School of Veterinary Medicine showed that out of 69 dogs participating in the study, 32 percent of the 11-year old dogs were affected, and 100 percent of the dogs 16 years of age older were affected, showing at least one sign consistent with cognitive dysfunction.
Increasing age results in some or all of the following changes in the brain:
• The brain atrophies. The total weight and size decreases, especially in the cerebral and cerebellar areas. The number of neurons, or brain cells, decreases, causing decreased brain function.
• There is an increase in beta amyloid plaques. Beta-amyloid is a protein that accumulates in the brain and damages neurons. The greater the beta-amyloid accumulation is, the greater the cognitive impairment. In dogs, errors in learning tests were strongly associated with increased deposition of beta-amyloid.
• Numerous micro-hemorrhages (bleeds) and infarcts (places where blood flow has stopped or been disrupted) can occur. These likely compromise overall blood flow and result in hypoxia (a reduced availability of oxygen).
• Changes in neurotransmitter levels. Monoamine oxidase B, or MAOB, has been found to increase in older dogs. MAOB metabolizes dopamine, a neurotransmitter, resulting in decreased dopamine levels.
Selegiline (L-Deprenyl, Anipryl) a medication used to treat Parkinson’s in people, helps to prolong dopamine activity. This may account for part of its help when treating cognitive dysfunction. In addition, since dopamine breakdown results in free radicals, it also helps reduce the amount of free radicals in the brain. Anecdotally, the earlier it is started, the better the result.
Certain Alzheimer’s medications that increase cerebral perfusion in people may have some benefit in CDS. Propentofylline (Karsivan, Vitofyllin) is licensed for use in some European countries for CDS/dullness/lethargy in old dogs. It exerts beneficial effects by improving blood flow to the brain.
Nutritional supplementation is an important aspect of management of this condition. The use of antioxidants (vitamins E and C, fruits, and vegetables), mitochondrial cofactors (e.g., Co-Q, S-adenosylmethionine or SAM-e), lipoic acid and carnitine, and nutriceuticals such as pyridoxine and ginkgo biloba have been shown to significantly improve cognitive function in aging dogs.
Some commercial therapeutic diets contain antioxidants, mitochondrial cofactors, and omega-3 fatty acids. These diets have been shown to improve the performance of a number of cognitive tasks when compared to older dogs on a non-supplemented diet. Improvements have been seen as early as to two to eight weeks after therapy begins.
But most importantly, environmental enrichment through increased physical activity and training with games and puzzle toys can help develop brain cells and improve cognitive function.
In humans, research shows that elderly people who are socially isolated and whose brains are under-stimulated are up to 68 percent more likely to develop Alzheimer’s or dementia. It seems that the same might be true of dogs. Several studies and ongoing research show that when a dog’s brain (and body) are exercised, his learning (or cognitive) ability improves. This might be due to the increased blood flow through major organs, including the brain, that comes with exercise.
In a laboratory study of older dogs over a two-year period, environmental enrichment (e.g., housing with another dog, playing daily with toys, increased game playing) was shown to be an effective tool for task learning. There are many interactive treat games and puzzle toys that are available to help stimulate canine nose work and brain work. Those made by Nina Ottosson (Nina-Ottosson.com/products) are good ones.
Additionally, training exercises to help strengthen a senior dog’s front and back limbs and core muscles will not only help reduce risk of falling or injury but will also help strengthen their cognitive function. Increased exercise and cardiovascular output are great ways to increase perfusion to the brain and also to release neurotransmitters and endorphins that help pick up appetite, mood, and increase interaction. A tired dog is a relaxed and happy dog that will likely have a better sleep schedule at nighttime.
Consider signing up for an exercise class with your senior pup to learn safe and effective training exercises to help engage your senior pup’s aging body and mind. Senior Pup-pilates is a six-week physical fitness class that combines training and activities to help your senior pet stay physically and mentally fit.
Additionally the book Remember Me?: Loving and Caring for a Dog With Cognitive Dysfunction by Eileen Anderson is a helpful resource for senior dog caregivers facing progressing signs of CDS. This book traces the author’s experience with her small terrier, Cricket, that developed canine cognitive dysfunction.
With proper care, senior dogs can be helped to manage the cognitive changes they will encounter as they age.
Ilana Strubel, D.V.M., heads up OrthoPets San Francisco, offering solutions for patients’ mobility problems in the San Francisco Bay Area where she currently owns and operates A Well Adjusted Pet–an Integrative Veterinary Physical Rehabilitation and Aquatic Fitness Center within the Rex Center in Pacifica. Find more info at AWellAdjustedPet.com.
Main article photo by: Photo Senior Pup-pilates SFSPCA courtesy of Ilana Strubel