Cushing’s Disease

Is your older horse taking longer to shed out than usual this spring? Is it getting harder to keep weight on the old man? Has your retiree had more than one hoof abscess in the last year? If so, you may be dealing with PPID, better known as Cushing’s Disease. Read on to learn more about PPID from this wise old cat!

What is PPID?

PPID stands for Pituitary Pars Intermedia Dysfunction, which is the technical term for Cushing’s disease in horses. In the most basic sense, PPID is a brain tumor. The brain actually has a very intricate system of glands that produce hormones which stimulate additional glands to produce other hormones that control functions elsewhere in the body. When one of these glands (the Pituitary) in the horse’s brain goes AWOL, you have Cushing’s disease.

The tumor growing on the pituitary gland is called an adenoma. This tumor applies pressure to the gland as it grows, causing over-production of its hormones (namely, adrenocorticotropic hormone, or ACTH). The clinical signs of Cushing’s disease in horses are all a result of too much ACTH in circulation. Time for a nap break…all of these letters are giving this cat a headache!

What are the signs of PPID?

Cushing’s disease can lead to a bunch of problems. For one, overproduction of ACTH can confound the whole winter-coat-growing system, so your horse winds up with long, curly hair in the hottest summer months. Failure to shed out completely or in a timely manner is the most well-known sign of Cushing’s disease. However, now that we know early treatment seems to slow the progression of the disease, our efforts are aimed at diagnosing the disease earlier, using more subtle signs.

In the early stages of the disease, PPID can cause lethargy, muscle wasting, regional fat deposits, recurrent infections, increased water consumption, and increased urination. The most worrisome side effect of Cushing’s disease is chronic laminitis. There is no known cure for laminitis, and it can even be life-threatening in horses with PPID. And that’s bad, because horses have 8 fewer lives than us cats.

Pony with Equine Cushings Disease

How do I know if my horse has PPID? 

Since the early signs of the disease can be subtle, our docs recommend annual testing for Cushing’s disease on any horse over 10 years of age. First the docs will draw blood, then it goes on a trip to Cornell University where they test the ACTH levels. Then, the doctors will compare your horse’s ACTH levels to the normal range for a horse during that time of year.

Considering your horse’s test results and clinical signs, your vet may recommend daily medication to treat PPID. Luckily, the folks at Boehringer Ingelheim have come up with a great medicine called Prascend that is easy to give, and works really well too! Just one tablet a day mixed in with grain is a sufficient dose for most horses. I’ve heard it tastes better than the cheese-flavored medicine the humans squirt in my mouth every day.

Conveniently, I have an event coming up here next week at Springhill Equine on Wednesday April 19th at 6:30pm, where you can learn all you ever wanted to know about PPID and other senior horse problems! Some of my favorite people from Boehringer Ingelheim will be there to answer any questions you may have, and best of all there will be food! Oh, and a chance to win a free ACTH test for your horse. You may think that is even better than food, but that’s where we will have to agree to disagree………

See you there!

-Tony