Cognitive Dysfunction in Cats

Pet Tales
by Barry B. Burtis D.V.M.

Most everyone is familiar with the adage that says cats have nine lives. It implies that cats have, over the centuries they have lived with us, built up quite a reputation for escaping life-threatening illness or injury and living to enjoy a ripe old age. Recently, studies show, cats are living longer than ever. In the United States, over the past 10 years, there has been a 15% increase in cats over 10 years of age.

There are probably a number of reasons for this increasing population of geriatric cats. Undoubtedly, a change in lifestyle for a majority of cats in Canada and the U.S. is a significant factor. A hundred years ago most cats were country cats. They were largely reliant on finding their own food which was not always easy, not always safe and not always successful. Today, most cats do not have these worries and by comparison with their predecessors lead quite luxurious lives. Even over more recent years, nutritional research has shown more specific dietary requirements for cats and commercially available diets provide these benefits at prices most cat owners can afford.

At the same time, the veterinary profession surely deserves some kudos for some equally impressive advancement in the health care cats now receive. Vaccinations prevent death from viral diseases, parasite control eliminates debilitating disorders that magnify the consequence of other disease, cures or controls for feline ailments that have existed as long as they have, are available. While most cat owners, I believe, are very pleased with these statistics proving a graying of the cat population, there are some consequences. One of these is the subject of this column.

Unfortunately, along with this growing geriatric population, there are increasing numbers of pets with signs of altered behaviour and apparent senility. These behavioural changes may result from many different causes. There are diseases that become more common in older cats that cause changes in behaviour, as well as other clinical signs. Diabetes and hyperthyroidism are two such diseases. True behaviour problems (separation anxiety, as an example) occur. Also, organic brain disease (for example, a brain tumour) and cognitive dysfunction can cause changes in behaviour. Diagnosis requires a full investigation of a cat's overall health, looking for any underlying illness, and a thorough assessment of the behaviour changes. Cognitive disorder syndrome (CDS) may be considered as a cause of problems only by ruling out other possible causes. CDS is a term that is applied to age-related deterioration of cognitive abilities, characterized by behavioural changes where no medical cause can be found.

The most commonly reported changes that occur in the behaviour of older cats include the following: spatial disorientation, e.g. getting trapped in corners or forgetting the location of the litter box; altered social relationships, either with their owners or other pets in the household - increased attention seeking or aggression; altered behavioural responses, e.g. increased irritability or anxiety or decreased response to stimuli; changes in sleep/wake patterns; inappropriate vocalization, e.g. loud crying at night; altered learning or memory, such as forgetting commands or breaks in housetraining changes in activity, e.g. aimless wandering or pacing or reduced activity; altered interest in food, either increased or more commonly, decreased; decreased grooming; temporal disorientation, e.g. forgetting that they have just been fed. CDS can cause all of these most common behavioural changes.

The cause of the syndrome is still unknown. It is theorized it may be due to compromised blood flow in the brain or cumulative effects of damage from free radicals, a process that results from less efficient cellular processes in the body, often associated with aging.

Next time, I want to discuss some of the things we can do to help behaviour problems associated with our pet cats now having ten lives.