Cognitive dysfunction syndrome, or CDS, describes an altered mental state of geriatric dogs and cats that resembles dementia in humans. According to Diane Frank, DVM, faculty of veterinary medicine at the University of Montreal, CDS in pets has four main characteristics: loss of recognition, loss of house training, disorientation, and changes in the sleep-wake cycle. There is no specific test for CDS, and many other disease processes can cause similar symptoms. The diagnosis of CDS is made by considering the age of the pet, confirming the presence of symptoms consistent with the syndrome, and by eliminating other medical conditions as causes for the cognitive changes.
Symptoms in Dogs
For dogs, Frank notes that symptoms of dementia can result from encephalitis, tumors of the brain, and hypothyroidism, or they may be unexplained. To rule out these other causes of cognitive dysfunction, your veterinarian will perform various blood tests, and may require additional testing including spinal fluid analysis, radiographs and ultrasound. If a brain tumor is suspected, an MRI may also be ordered.
Symptoms in Cats
Older cats also suffer from cognitive dysfunction syndrome. According to Danielle Gunn-Moore, BVM&S and a specialist in feline medicine from the University of Edinburgh, cats with CDS show many of the same symptoms as dogs, but they are also likely to show increased night time vocalizations, decreased grooming activity, and declining interest in food. She also warns owners and veterinarians to consider the possibility of osteoarthritis in elderly cats who show symptoms of CDS. As Dr. Gunn-Moore explains, “The importance of arthritis should not be overlooked. Radiographic evidence of degenerative joint disease is present in 70 to 90 percent of cats over 10 years of age. Associated pain and/or dysfunction can result in reduced activity and mobility, aggression, altered interactions with the family and/or loss of litter box training.” These symptoms of arthritis in cats mimic the symptoms of CDS, but will improve with pain management in the case of osteoarthritis.
Treatment for CDS in both dogs and cats includes a combination of environmental management and medical therapy. Selegine is a medication labeled for use in dogs to treat CDS. There is no medication labeled for use in cats to treat CDS, but the American Association of Feline Practitioners supports use of selegine as an off-label drug for treatment of CDS in cats. Environmental management of dogs with CDS should be aimed at simplifying access to food and water, and providing them with frequent access to sanctioned bathroom areas in order to reduce house soiling accidents. Cats might benefit more from having their living areas restricted to a smaller area – once they display symptoms of CDS they are less likely to tolerate changes in their environment and can feel more secure in smaller spaces.