Cat's Gone Crazy? No, Just Senile

Aug. 14, 2007 — Mental disorders associated with aging, including Alzheimer's, are far more common in domesticated cats than previously realized, with more than half of all cats over age 15 showing signs of senility, according to a forthcoming Journal of Small Animal Practice paper.

The findings support a growing body of evidence suggesting that most, if not all, mammals, can suffer age-related conditions normally associated with people.

In the case of cats, the main difference is that a 15-year-old individual can be compared to an 85-year-old person. Another recent study found that about half of all octogenarians, too, show signs of dementia.

The behaviors associated with senility in cats range from acting disoriented to changes in their social relationships, to shifting sleep habits, said lead author Danielle Gunn-Moore, head of the Feline Clinic at the University of Edinburgh's Hospital for Small Animals.

They may also include inappropriate vocalizing, forgetting commands, breaking housetraining, pacing, wandering, sluggishness, unusual interest or disinterest in food, and decreased grooming and confusion, such as "forgetting that they have just been fed," said Gunn-Moore.

These behaviors can also be associated with other health conditions, such as thyroid problems and diabetes. To rule out those possibilities, one of Gunn-Moore's team members, Kelly Moffat of Arizona's Mesa Animal Hospital, conducted a study on 154 geriatric cats brought to local vets.

Based on Moffat's results, the researchers concluded that 28 percent of pet cats aged 11 to 14 develop at least one brain-linked behavior problem associated with aging. That percentage then jumps to over 50 for cats 15 years or older.

Together, Moffat, Gunn-Moore and other researchers then focused on the aged cats' brains, using X-rays and post-mortem analysis. They identified thick, gritty plaques on the outside of the cats' brain cells. The plaques contained an Alzheimer-like protein that interferes with brain messaging.

This protein is "crucial to our understanding of the aging process in cats," Gunn-Moore said. "We've known for a long time that cats develop dementia, but this study tells us that the cat's neural system is being compromised in a similar fashion to what we see in human Alzheimer's sufferers."

Rebecca Wood, chief executive of the Alzheimer's Research Trust in England, expressed interest in the findings and said, "Many people will be surprised by the fact that domestic cats can develop a form of Alzheimer's, just like their owners."

Wood added that pets are also living longer "so this type of distressing disease is only going to get more common."

Gunn-Moore believes that good diet, mental stimulation and companionship appear to reduce the risk of dementia in both humans and cats.

"If humans and their cats live in a poor environment with little company and stimulation, they are both at higher risk of dementia," she said. "However, if the owner plays with the cat, it is good for both human and cat."

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