Signs of Equine Dementia

Q:I have a 28-year-old Welsh Mountain Pony cross. He has recently developed an almost senile characteristic. He stands and loses his whereabouts, looks dazed, and doesn't seem as sharp as he normally is. He is a rescue pony and used to be very spooky, but this seems to have stopped. He seems worse in the dark but he snaps in and out of it much like a human with dementia does.

Is dementia, or something along those lines, something that develops in horses? Can it be treated or helped to improve? I'd appreciate any advice.

Nicole Lee, Kent, England

A:I referred your question to Amy Johnson, DVM, Dipl. ACVIM, who is our equine neurologist here at New Bolton Center. Here is her reply:

Dementia has not been well-described in the horse. However, scientists have observed an age-related syndrome similar to dementia in elderly dogs and cats that likely occurs in other species as well. This problem, "cognitive dysfunction syndrome," is best described in dogs. Interestingly, the brains of dogs that have cognitive dysfunction show pathologic changes similar to those that occur in people with Alzheimer's disease. So, just because scientists have not formally recognized equine dementia in the horse does not mean it does not occur, and in all likelihood aged horses might suffer from some of the same age-related structural brain changes that occur in other species.

Of course, we must consider other possibilities for behavior changes in horses such as brain tumors or metabolic diseases. It would be prudent to have a veterinarian perform complete blood work, including a biochemistry panel, and a complete neurologic examination to ensure there are no signs of a disease process that could be affecting your horse's behavior.

Just as there is no known cure for Alzheimer's, there is no known cure for cognitive dysfunction syndrome, and the same is likely true for equine dementialike syndromes. Veterinarians have used some drugs to improve cognitive dysfunction in dogs, with reported improvement, but I am unaware of them being used in horses for this purpose and can't even speculate whether they would be effective.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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