Getting up from my desk, I stride purposefully to the kitchen, then stop. Why did I come in here? I can’t recall. I give up and go back to my desk. Oh, right, I was looking for scissors. My 91-year-old mother forgets that she called at lunchtime, and phones again during dinner. My husband? Well, let’s just call him absent-minded. We all joke about senior moments, about looking for glasses that are perched atop our heads, but when do behavioral changes cross the line from normal aging into pathology? When do we need to worry when a loved one seems confused? And what about when that loved one is your dog?
Cognitive Dysfunction Syndrome (CDS) in veterinary medicine is defined as a decline in behavioral functioning associated with advanced age, in the absence of any identifiable physical or medical explanation. It’s also called “senility” or even “dementia,” and the terms can get confusing. In human medicine, dementia isn’t technically a specific disease, but rather a collection of symptoms affecting memory, and cognitive and social functions. There are many different causes of dementia in people, including diseases such as Alzheimer’s. Definitive diagnosis can be difficult — even more so when we are talking about pets. We rarely do extensive neurological diagnostics in very elderly animals, nor can we use the kind of question-and-answer tests that people take to assess memory, language skills, and problem-solving abilities. Instead, veterinarians depend on physical examination, laboratory tests to rule out other illnesses, and asking you, the owner, a series of questions about your pet’s behavior.
Let’s take a hypothetical patient. We’ll call him Flubber. Since there does appear to be a genetic tendency for CDS, Flubber may have a family history of similar senility issues in his line, but CDS can occur in any breed. Age of onset is usually 11 years or older, but some signs may be seen even younger, especially in larger-breed dogs. Symptoms can range from mild to severe. At first Flubber may just seem needier, or more anxious than usual. He may exhibit disorientation or confusion, wandering, staring at walls, moving to unusual places, getting “lost” in the house, or going to the wrong door when asking to go out. Disturbances in the sleep-wake cycle may lead to nighttime waking, restlessness, and irritability. Decreased activity levels, or conversely, increased purposeless or repetitive activity like pacing may occur. Flubber may vocalize inappropriately — howling, barking, or whining without apparent cause. He may be less interested in social interactions, or show an increase in aggressiveness. Altered learning and memory may be evidenced by reduced response to previously learned commands (like sit and stay) and/or loss of housebreaking.
Since many of these symptoms may have other medical explanation, Flubber should get a complete physical exam and laboratory workup. Urinating in the house may be the result of a bladder infection, or a weak urinary sphincter. Arthritis can impede mobility, making him less active, and disturb his sleep. All this can make him whiny and irritable. Older animals also frequently suffer from “sensory deprivation.” In other words, Flubber’s vision, hearing, and/or sense of smell may be declining. The fact that he doesn’t come when you call or seems disoriented may not indicate CDS. He may simply not be able to hear you, see you, or smell you. All these things can understandably exacerbate anxiety. But if Flubber’s symptoms exceed any physical explanations and everything else checks out normally, then we may make a presumptive diagnosis of CDS. Now what?
There is no cure for CDS. Some veterinarians recommend feeding a diet such as Hills B/D that is fortified with antioxidants, essential fatty acids, and other supplements, which may support cognitive function and delay the decline. What about medications? Selegiline, a medication used to treat Parkinson’s disease in people, is marketed for dogs under the brand name Anipryl, and licensed for treatment of canine CDS. Results are erratic, but I have had some success using it, particularly for loss of housebreaking and sleep-cycle issues. Otherwise, we just try to treat individual symptoms: Antianxiety medications if he’s anxious. Pain medication if he’s in pain. Sedatives if needed to help him sleep through the night.
Everything else is supportive care. Eliminate things that make Flubber anxious. Is that slippery parquet floor scary? Rubber-backed throw rugs will improve the footing. Afraid of the stairs? Put up baby gates so he doesn’t take a tumble. Always assist with a reassuring hand on his collar when he has to go up or down. If he’s little, carry him. For separation anxiety, try leaving music playing, or the TV on. If dealing with loss of housebreaking, keep a regular schedule of meals and walks. Take him out often; don’t wait for him to ask. Just take him. Keeping track of when he urinates and defecates may help you predict his body’s routine and avoid the unexpected. The more consistent life is, the less confused he will be. When you are not home, confine him to an area where he can’t get into trouble, and where it won’t be a problem if he has an accident. Consider giving him a place where he can eliminate inside. There are many products on the market for just this purpose that will make cleanup easier.
Caring for a pet with CDS requires patience and willingness to make accommodations. Reward normal, interactive behavior. Provide mental stimulation. Keep him moving, within the bounds of his physical limitations. All this may slow the clinical progression of his CDS. He can’t do sudoku, but you can introduce new toys regularly. He can’t hike Peaked Hill, but you can take a little walk every day, or play a slow game of geriatric fetch. He may no longer be the vivacious companion he was in his youth, but with a little extra effort, the bond you share may well outweigh the challenges of CDS…. Now where did I leave my glasses?