Alzheimer's disease, which damages the human brain in ways that impair memory, learning and thought processes, has a canine counterpart with similar signs and symptoms. Canine cognitive disorder, also known as canine cognitive dysfunction syndrome and "doggy dementia," is a neurological disease that strikes some dogs in their senior years. If caught early, the progression can often be slowed by drugs and the symptoms managed with home care. If your elderly dog starts showing signs of confusion and disorientation, have him checked out by a veterinarian as soon as possible, advises VCA Animal Hospitals.
Behavioral Changes in Affected Dogs
Estimates of the prevalence of canine cognitive disorder vary widely. But according to Margaret Gruen, assistant professor of veterinary medicine at North Carolina State University, some studies indicate that 28 percent of dogs aged 11 to 12, and 68 percent of dogs aged 15 to 16, show at least one sign of it. The acronym DISHA is often cited as a way to remember key symptoms: disorientation, changes in usual patterns of social interactions with people or other animals, sleep disturbances, house soiling accidents and altered activity levels. Indications of departures from normal psychological states such as heightened anxiety, restlessness and the emergence of new fears or phobias may be warning signs.
How Vets Diagnose Dementia in Dogs
Canine cognitive disorder is a "default" diagnosis that vets only make after ruling out all other possible causes for symptoms. The reason is that senior dogs often suffer from more than one medical problem that causes pain and thus anxiety, irritability and decreased mobility. A short list includes arthritis, cancer, hypothyroidism, brain tumor, urinary tract infections and a range of metabolic disorders. An elderly dog who stops coming when he's called might have impaired hearing; one who bumps into things might have deteriorating vision. If a dog starts urinating or defecating in the house, the problem might be behavioral, not neurological. After the vet is satisfied that no other explanation accounts for symptoms consistent with dementia in senior dogs, canine cognitive disorder is the only diagnosis remaining.
What Brain Analysis Often Shows
Most of the time, only post-mortem analysis of the brain structure and tissue can definitively establish Alzheimer's disease in people and canine cognitive disorder in dogs. One feature often shared by both diseases is the presence of neurotoxic protein deposits called amyloids, which both kill brain cells and block established channels of communication among neurons. Sometimes, though, scans by magnetic resonance imaging, or MRI, reveal abnormalities in the brain structure of living dogs with canine cognitive disorder, says Annie Chen-Allen, assistant professor of neurology and neurosurgery at Washington State University's College of Veterinary Medicine. The brain may appear atrophied, especially in two regions responsible for memory and awareness, the hippocampus and cerebral cortex. The normal symmetry between the right and left hemispheres can be off. And ventricles, reservoirs for cerebrospinal fluid, may be enlarged.
Managing and Treating Canine Dementia
Pet owners must understand that while dementia is chronic and progressive, much can be done "to maintain function and quality of life for both patient and caregiver for as long as possible," writes Margaret Gruen, author of the "Clinician's Brief" on cognitive dysfunction in dogs and cats published in December 2013. Several prescription drugs can help to stabilize the condition, ease symptoms and regulate sleep cycles. Dietary changes and nutritional supplements can have beneficial effects on stimulating the brain and improving cognitive function. Sticking to a regular schedule for walks, feeding and playtime; providing opportunities for physical and mental stimulation in the form of food puzzle toys and games; and offering incontinent dogs a place to relieve themselves indoors are all measures that can help relieve stress, Gruen says.