Cognitive Dysfunction

Few Treatment Options Exist for Senior Cats

Does your older cat howl or whine at inappropriate times in the middle of night? Does he seem anxious or fearful? Is he irritable or aggressive with the other cat or dog in the household after years of harmony? Does he ever seem confused or disoriented? If so, he may be showing signs of the feline version of Alzheimers disease.

Although widely accepted as a condition in humans and dogs, cognitive dysfunction, which is roughly comparable to Alzheimers disease in humans, is not well documented in cats because its not as obvious as in dogs, says Kelly Moffat, DVM, a veterinarian at Mesa Veterinary Hospital in Mesa, Arizona. Moffat is studying cognitive dysfunction – that is, impairments in thinking-related skills – in a group of cats. Dogs are expected to obey simple commands, tolerate more handling, and possibly exercise and interact more with humans. We dont hold that same standard to cats, she says.

When older cats start acting strangely, their human companions usually dont mind the changes the way they do with their dogs and so dont necessarily even mention these changes to the veterinarian, she says. Many people, she adds, also incorrectly assume that the changes are normal or untreatable effects of aging.

Physical signs similar to those in dogs, humans
However, now that were looking for the disorder in cats, the findings of preliminary studies suggest that many of the behavioral changes typical of cognitive dysfunction in dogs also occur in elderly cats, but the age of onset may be higher in cats, says Gary Landsberg, DVM, a veterinarian at the Doncaster Animal Clinic in Ontario who is collaborating with Moffat on the study of cognitive dysfunction in 150 feline old-timers. Researchers also are finding similar physical changes, such as collections of plaque, in feline brains as in canine and human brains in the early stages of Alzheimers disease. Moffat is hoping to study enough feline brains, comparing those of geriatric cats both with and without behavioral changes, to make more definitive conclusions.

Thanks to good nutrition and modern veterinary care, cats are living longer than ever; as a result veterinarians expect to see more and more cases of cognitive dysfunction in cats. But before they can make a diagnosis, they must rule out other causes of similar behavioral changes. The veterinarian will need to perform a physical and neurological exam and blood and urine tests to rule out a host of conditions, such as thyroid, liver, and kidney problems, hearing or vision loss, neurological diseases such as brain tumors, heart disease, high blood pressure, and infectious diseases such as those caused by feline leukemia virus and feline immunodeficiency virus.

Treatment options are limited
If no other medical condition can be detected, the veterinarian is likely to diagnose the behavioral changes as cognitive dysfunction. Although theres no cure, veterinarians often prescribe for dogs the medication Anipryl, the veterinary trade name for a drug called selegiline hydrochloride, also known as L-deprenyl. In humans, the medication is used for treating Parkinson’s disease and Alzheimers disease. However, Anipryl, which is effective in reversing symptoms in about 70 percent of dogs, is not licensed for use in cats. Landsberg, who conducted some of the trials with Anipryl in its testing phase in dogs, has administered the drug, which would cost about a dollar a day for cats, to about 35 cats with cognitive dysfunction, and thinks it may be helpful.

But using Anipryl in cats is very experimental, he says. The drug and its toxicity have not been tested in cats, so its not something we can currently recommend. For now, a veterinarian treating a cat with cognitive dysfunction doesnt have a lot of options. He or she may suggest antianxiety drugs for the cat in the short-term or antidepressants in the long-term to see if the signs can be minimized. Environmental enrichment – toys, games, and play centers – is also recommended. Encouraging the cat to interact, engage in exercise, and learn basic commands can aid in keeping the cat mentally and physically fit, Moffat says.

Personality changes a common sign
Moffat believes that cognitive dysfunction in cats is quite common, though a bit less so than in dogs. One recent survey of 180 geriatric dogs between the ages of 11 and 16 with no known ailments found that almost two-thirds of the dogs showed at least one sign of cognitive decline, specifically either failure in housetraining, changes in sleep patterns, disorientation, or changes in sociability. Cats begin to enter their geriatric phase at around age 11 and can live for more than 20 years.

Although cognitive dysfunction itself is not fatal, the cat undergoes increasingly severe personality changes which can make caring for an afflicted cat burdensome and frustrating. So much so, says Moffat, that the cat is often euthanized. Even though more cats are living to 20 years and veterinarians are beginning to see more cats with probable cognitive dysfunction, some cats – so-called graceful agers – are never affected with any signs of cognitive dysfunction.

Although we dont know that much about feline cognitive dysfunction yet, we do not believe that it is part of normal aging, just as Alzheimers disease does not strike all elderly humans, says Landsberg, who points out that geriatric cats and their behavior changes should be checked out by their veterinarian.