About Equine Cushing's Disease

Cushing Disease in horses is easy to diagnose, but many times missed until it is at its most severe stages. It is most common in older horses, causing long thick coats, weight loss, loss of muscle and more water consumption. Many times Cushing Disease is overlooked because these same symptoms can happen in an older horse. Although these is no cure for Cushings, there is treatment that can help suppress symptoms.

  1. Cause

    • Cushings Disease is caused by either a tumor that grows on the pituitary gland or hypertrophy of the gland. Either way, as the pituitary gland become crowded, it begins to waver in the amounts of hormones it sends out to the body. Generally, as the size increases, it works overtime and begins to affect the part of the hypothalamus that regulates the horse's body temperature. In the end, after Cushings Disease has set in, the horse becomes very uncomfortable because its body can no longer self-regulate and needs human interaction to relieve the discomfort.

    Symptoms

    • General symptoms of Cushings Disease are long hair, a pot belly, loss of muscle and drinking a lot of water year-round. Things can be worse for these horses, and not only in appearance. Cushings horses tend to have a higher amount of cortisol which affects their immune system. They are more susceptible to infections, abscesses and bacteria. In the meantime, their metabolism is picking up, not allowing them to utilize protein, so their muscle and body begins to shrink. These horse become extremely lethargic, thirsty, sweat a lot and just become uncomfortable. In the worst case scenario, a horse with Cushings Disease will eventually founder from all the stress on his body.

    Testing

    • There are a few ways to test for Cushings, including tests made specifically for it. A simple way to test is by giving a horse dexamethasone, which is a type of corticosteroid, just like cortisol. A healthy horse's pituitary gland will shut down, while a horse with Cushings will continue to produce cortisol. The tests made for Cushings disease use dexamethasone in the same fashion. Another test is to monitor the cortisol levels morning and night for 30 days. Cortisol should be higher in the morning than at night by about 30 percent.

    Treatment

    • There are two different types of medicine that are popular for treating Cushings Disease. One is Pergolide, a drug that shuts down the pituitary gland by stimulating dopamines. This is the same medicine used in humans with Parkinson's Disease. The original drug used for Cushings Disease is cyproheptadine, but it is not thought to work as well as Pergolide. The two combined, though, seem to work well in some cases.

    Feeding and Supplements

    • Through feeding and certain supplements you can help a horse with Cushings Disease. High sugar and starch diets are not suggested, so a grass hay and simple pellet is a better source of food for these horses. Vitamins E and C are highly recommended, along with other antioxidants, for a horse with Cushings. Chasteberry is the newest supplement that is thought to work to release dopamines.