Equine Cushing's Disease

What is it? This is a slowly progressive disorder that occurs fairly common in middle-aged and old horses and ponies. It is caused by a tumor in the pituitary gland in the brain, which affects the function of the adrenal glands and causes them to over-secrete various hormones.

Patient Profile:

• Middle-aged to older horses and ponies. (Average age 19 years).
• Females appear to develop the disease more frequently than males.
• Ponies appear to develop the disease more frequently than horses.
• No breed pre-disposition – all breeds are affected.

 Clinical Signs Can Include:

• Excessively long, shaggy and/or curly haircoat, often most noticeable on the limbs. Also, failure to seasonally shed hair.
• Excessive sweating, in some cases even when the horse is at rest.
• Muscle wasting, weight loss, "sway-backed" and/or "pot-bellied" appearance.
• Increased drinking and urination.
• Increased susceptibility to bacterial and parasitic infections.
• Increased incidence of laminitis (founder) and sole abscesses.
• Changes in attitude and behavior, such as lethargy and dullness.
• Other signs can include increased respiratory rate, changes in appetite, and abnormal estrous behavior in mares.

 Treatment: If your horse fits into this clinical picture, we may suggest a simple “Dexamethasone suppression test” to gain more information. There is no other clinical condition in the horse that causes a long shaggy haircoat so this is often considered diagnostic.

 Excellent management is essential to keep your horse healthy for as long as possible. This includes highly-nutritious, easily-chewed feed, adequate water supply, regular deworming, dental and foot care, and body-clipping in hot weather if necessary.

 There are medical treatments available. These will not cure the disease, but will maintain the horse for a period of time. One treatment is more expensive than the other but affordable and we would be happy to discuss them with you if you are interested.

 This information is provided as an educational tool and is not intended to replace veterinary care. Please call our office if you have any questions!