What is Cushing’s Disease (Pars Intermedia Dysfunction)?
Equine Cushing’s disease results from a malfunction of the pituitary gland (a part of the brain) more specifically the pars intermedia hence the name pars intermedia dysfunction.  The pituitary gland over-secretes certain hormones that result in the common clinical signs seen with the disease.  Cushing’s Disease is very common and occurs in older horses.

Common clinical signs seem with Cushing’s Disease include: a long, shaggy haircoat, an abnormal shedding pattern, such as retention of long hairs in the jugular grove, on legs, along the bottom of the abdomen, delayed shedding in the spring or early coat development prior to winter.  Other clinical signs include: decreased activity level, laminitis, increased thirst, increased urination, excessive sweating, increased susceptibility to infections, loss of muscle mass and abnormal deposition of fats.  Some other signs include a decrease in appetite with subsequent weight loss, a potbelly appearance and bulging supraorbital fat pads (bulges just above the eyes).

Cushing’s Disease is diagnosed via a blood test to evaluate if there is an overproduction of the hormones that are responsible for the clinical signs.  The disease is non-curable but can be managed with lifelong medications such as pergolide.  Pergolide suppresses the overproduction of the hormones and can reverse some if not most of the clinical signs as long as the horse is on the medication.  In addition, secondary problems that may have developed such as laminitis or infections must be also treated with assistance of your veterinarian & farrier.

If your horse is 15 years old or older than you may want to consider having a Cushing’s Disease screening test performed especially if any of the clinical signs above are present.  Our clinic has a geriatric wellness program in place that evaluates for Cushing’s Disease along with other diseases/ailments that are common among older horses.  The screening test should be performed in the spring or summer months and should be performed every 1-2 years to prevent secondary problems such as laminitis from occurring.  In addition, if your horse has been previously diagnosed with Cushing’s Disease it is recommended to have a blood test performed every 6-12 months during the spring or summer months to ensure that your horse is on the most appropriate amount of medications.