Cognitive Deterioration in Cats Shows Similarities to Alzheimer's in Humans, Offering Potential for Joint Research Advancements in Both Species
In a groundbreaking study published in the European Journal of Neuroscience, researchers from the University of Edinburgh have discovered that the brain changes in cats with dementia are strikingly similar to those found in humans with Alzheimer's disease.
The study, led by Dr. Robert McGeachan, examined the brains of 25 cats after death, some of which had shown signs of feline cognitive dysfunction syndrome (CDS) in life. The findings revealed that amyloid-beta, a toxic protein one of Alzheimer's defining features, was more abundant in aged and CDS-affected cats than in young cats.
This build-up of amyloid-beta protein in the brain is a critical finding, as it is linked to Alzheimer's and found in the synapses (connections between brain cells) in cats with dementia, just as it is in humans with Alzheimer's. The amount of engulfed, amyloid-laden synapses correlated with the overall amyloid burden in cats with dementia but not in cognitively healthy aged cats.
The study also found that in regions rich in amyloid-beta plaques, microglia and astrocytes contained pieces of synapses in cats with dementia. This suggests that amyloid-beta may be triggering the brain's own immune cells to engulf synapses, a process that can accelerate cognitive decline in disease.
The similarities between feline dementia and human Alzheimer's disease don't end with brain pathology. Both conditions also share clinical symptoms such as confusion, increased vocalization (in cats, more meowing), disrupted sleep, and behavioral changes. In fact, more than a quarter of cats aged 11 to 14 show at least one sign of dementia, and the number jumps to about half in cats over 15.
These findings are significant because cats naturally develop dementia, unlike genetically modified rodent models. As a result, feline dementia could serve as a powerful natural model for the human condition, potentially accelerating the search for treatments for Alzheimer's disease.
The study opens the door to testing whether new Alzheimer's treatments might help ageing pets. Subtle symptoms of dementia in cats include asking for food at odd times, sleeping in unusual patterns, waiting at the window for people who aren't due home, or seeming indifferent to affection from those they once loved.
A short video of a cat named Maolo lingering outside a door went viral on social media, drawing thousands of sympathetic comments. While Maolo's story is heartbreaking, it also highlights the importance of understanding feline dementia and its connection to Alzheimer's disease.
Understanding these parallels could help develop treatments benefiting both ageing cats and human Alzheimer's patients. By studying feline dementia, researchers may be able to gain valuable insights into the causes and progression of Alzheimer's disease, potentially leading to new treatments and a brighter future for both cats and humans.
