The FEI & FDA Drug Drama of Equine Cushing’s Disease

Thousands of horses of all breeds, ages, genders, and disciplines are diagnosed with this complicated disease each year, and FEI and the FDA aren’t making the diagnosis any easier (or cheaper) to swallow. 

Top photo: Wikipedia France

 The Culprit

Cushing’s, known less commonly as Pars Intermedia Pituitary Dysfunction (or PPID),  causes a horse’s pituitary gland to go into overdrive, which can cause cosmetic symptoms like abnormal hair coat and more serious symptoms like laminitis. It is as common as affecting 1 in 7 horses over the age of 15, but it can also be diagnosed in horses as young as four although that is less common.  By far the most frustrating part of owning a horse with Cushing’s is that in order to prevent life-threating and/or permanent physical complications, a Cushing’s horse’s diet, exercise regimen, and soundness will have to be monitored and measured constantly for the rest of its life. It will also almost certainly require a daily medication of a drug known as pergolide, now also known as Prascend.

One Drug to Rule Them All

Pergolide has been the universal treatment for Cushing’s horses for several years, and was first developed for humans with Parkinson’s until was pulled from the human market in 2007 because of concerns that it caused heart problems and possibly affected decision centers in the brain. (Freaky pergolide side note: more than 100 Australian citizens who used pergolide are suing the manufacturer because they claim it caused gambling and sex addictions. WEIRD.)

For a lot of boring legal jargon reasons, when the drug was discontinued for humans, the drug companies had the drug approved specifically for equine use by the FDA in 2012. This has some huge ramifications for the Cushing’s community, and some of the effects are only being felt now. Many veterinarians had stockpiled the drug before FDA approval, and have been continuing to distribute it to clients via prescription (the FDA allows this so that materials already manufactured don’t go to waste). But now those stockpiles are running low (or ran out quite a while ago, depending on your vet and your area), and the only legal option is a drug that easily costs about twice as much (about $60 a month for the average dose appears to be the going rate online).

If that isn’t bad enough, Heaven forbid your cushing’s horse happens to also be a world class prospect or veteran of an FEI sport, because the only drug in the world that treats your horse’s symptoms and which they should not be taken off of for any period of time is a controlled substance on the FEI drug list. While there are FEI Equine Therapeutic Use Exemptions for controlled substances, these are virtually never granted for long term treatment of chronic conditions such as Cushing’s.

Alternative Remedies

Some have chosen to go it alone down the road of homeopathic or all-natural remedies to treat Cushing’s, and claim great success. Hilary Hilton of Hilton Herbs USA markets a product called Vitex Plus for Cushing’s horses that combines a long-rumored treatment of agnus castus seed, also known as chasteberry, with goats rue herb, bilberry fruit, artichoke leaf, bruised milk thistle seed, and golden rod herb. She and many clients claim great success with the product, despite a medical study in the early 2000’s that found chasteberry to be a ineffective treatment of PPID. (A second study conducted at around the same time had more positive outcomes.) The product is not necessarily less expensive, but based off a search for the ingredients in the FEI Banned Substance App, this could be an alternative for a horse competing in recognized events who responded positively to the natural treatment.

There is another workaround of requesting compounded drugs, which means that your veterinarian can write a prescription for a proprietary blend of ingredients that would be formulated by a compounding pharmacy. If one of those ingredients is pergolide, they might be able to develop a less expensive option. But the FDA is cracking down on veterinarians writing too many compounding prescriptions for the drug, and in turn veterinarians are increasingly more reluctant to write them. Moreover, not all compounding pharmacies are created equal, and compounded prescriptions can be less stable and more risky depending on the pharmacy and its practices. There is a great article on this subject here.

The Moral of the Story

Having a horse with Cushing’s is an inevitable pain in the neck, the wallet, and the heart. But if your Cushing’s horse is anything like the rockstar lesson pony at my barn, it’s worth every bit of the agony.

Photo by Casey Raubenheimer

DISCLAIMER: This is your friendly Horse Nation reminder that we claim to be neither experts nor vets, so if you have questions about your horse’s individual treatment options, ALWAYS consult a professional. We know you will!

Additional Resources for Owners of Horses with Cushing’s:

The Equine Cushing’s Disease Facebook Group 

An Owner’s PPID Community Network (via the prascend brand)

The Healing Barn offers some information for those exploring natural remedies

Go Riding!