Cats Get Dementia Just Like People, Making Them a Potential Research Tool

SATURDAY, Sept. 6, 2025 (HealthDay News) — Just like their human counterparts, cats may act cranky or confused and have trouble sleeping as they age. 

They may even yowl more than usual at night.

These, researchers say, are dementia-like behaviors that may owe to an accumulation of plaques in their brain, just like those in people with Alzheimer’s disease.

And this similarity might mean that cats could offer scientists an important new model of human Alzheimer’s and how to treat the irreversible disease. 

"It’s exciting to have a naturally occurring model," Roberta Marongiu, a neuroscientist at Weill Cornell Medicine in New York City, said in a news release.

She was reacting to findings of a study published recently in the European Journal of Neuroscience.

In their work, researchers studying Alzheimer’s generally use mice that have been genetically modified to develop the disease.

But cats develop dementia naturally, just like people, which could make them a valuable resource. As with people, amyloid-beta plaques build up in their brains. 

Researchers suspect that this buildup could be causing a cascade of problems within cats’ brain — for example, activating immune cells that attack links between nerve cells. These links are called synapses.

Earlier research had found amyloid beta in cats’ brains, but scientists didn’t know how much it was affecting the animals’ brain function.

Dr. Robert McGeachan, a veterinarian at the University of Edinburgh in Scotland, and his team knew, however, that the number of synapses dropped early on in people with Alzheimer’s. So they zeroed in on these connections in their cat study.

They looked at brains preserved from seven young cats and 18 older ones that had died. Those included eight that exhibited behavior signs of dementia.

Using fluorescent markers that cling to amyloid beta, they found that the old cats had more of the protein than the younger ones did. And the amyloid beta plaques in the seniors tended to build up around synapses, the study found.

Meanwhile, in the older cats, immune cells that regulate inflammation and help maintain a healthy brain environment were in overdrive. And they seemed to lurk near the amyloid-beta clumps. 

Instead of only attacking the clumps, however, they also seemed to be attacking some synapses, the study found.

And that, said Marongiu, who reviewed the findings, mimics what happens in the brains of people with Alzheimer’s.

McGeachan and his team are continuing to study more brains in search of other patterns between cats with and without dementia. 

They also plan to investigate how other hallmarks of Alzheimer’s, such as the buildup of tau protein, show up in cats’ brains.

Although cats are unlikely to replace mice as model animals for Alzheimer’s — in part, because they are more costly — more research is likely to benefit them, too, McGeachan said.

"We can improve health for humans and for animals," he said.

More information

The Alzheimer’s Association has more about dementia.

SOURCE: Science News, Aug. 26, 2025

What This Means For You

Scientists are learning more about the underpinnings of Alzheimer's disease and other dementias.