Equine Cushing’s Disease

Definitely more than just “old age,” Equine Cushing’s Disease, or Pituitary Pars Intermedia Dysfunction (PPID) as it is also known, is being seen more now that advances in veterinary medicine are allowing our equine friends to live longer lives. Ponies appear to be at greatest risk of developing this disease although all breeds, genders, and types of horses are potentially susceptible. It is rare to see Cushing’s in a horse under the age of 15 and more common to see it in horses who are in their 20s or 30s.
Characterized by a heavy, coarse, wavy or curly haircoat that does not shed as expected, other symptoms of Cushing’s are often vague and can be easily attributed to other conditions or even just the fact that your horse is aging. Some of these include weight loss; lethargy; loss of muscle mass, particularly over the topline; the development of fat deposits, especially over the tail head, above and behind the eyes, and along the crest of the neck; increased drinking and urination; recurrent infections; laminitis and a rounded abdomen or potbelly.

Cushing’s is caused by a tumor in the pituitary gland, sometimes referred to as the “master gland” because it regulates nearly all of the body’s endocrine systems. These tumors are benign, but due to the proximity to the brain are considered “active” tumors. Typically a slow-growing tumor, the size seems to have little correlation as to whether your horse will have a severe or mild case of Cushing’s. Surgery to remove the tumor is not an option, but fortunately, Cushing’s is relatively easy to manage with medication.

Horses afflicted with Cushing’s also generally have immune systems that are compromised. As such, they are more susceptible to internal parasites, periodontal disease, sinus infections, hoof abscesses, and laminitis. In addition to medication to help control and slow the progression of Cushing’s, preventive care strategies become more important to the continued quality of life and management of health than in horses not similarly afflicted. Horses diagnosed with Cushing’s should be on a minimum twice-yearly preventive care exam schedule which should include frequent dental checkups and be supplemented by regular farrier visits. It is also important to establish and maintain a deworming protocol that takes into account your horse’s increased susceptibility to parasites and to evaluate its effectiveness with periodic fecal egg counts. Ensuring your horse is receiving a diet that will keep her healthy and not exacerbate her symptoms and ensuring a good balance of minerals with supplements as necessary will help your horse stay in the best condition possible. It is important to ensure both the diet and any supplements are balanced and that supplementation is necessary to avoid introducing any additional complications such as a mineral toxicity into the mix.

Early diagnosis followed by aggressive treatment can not only help prevent and address complications, but it can also help extend your horse’s lifespan while maintaining a quality of life. Cushing’s in horses cannot be cured, but with a good plan that is implemented and maintained, your horse will still be able to enjoy her life and your company to the fullest.