Ever wondered why your little pony seems to have a long hair coat even in the warmer months, or why he or she keeps getting bouts of laminitis again and again even though you’ve tried so hard to prevent it? Well, you’re pony may in fact be suffering from Equine Cushing’s disease.


What is Cushing’s disease?
Cushing’s disease is the most common hormonal condition seen in older horses and ponies.

Cushing’s is more often seen in pony breeds, but larger breeds can be affected and it is primarily seen in older horses above the age of 15 years. Equine Cushing’s is usually caused by a benign tumour (adenoma) of the pituitary gland in the brain. This tumour results in a higher than normal level of circulating cortisol (a stress hormone) within the blood. It is this over production of cortisol that affects the horse and can explain the majority of clinical signs seen in this condition. The location of the tumour can explain some of the rest.

What are the signs of Cushing’s?

  • Abnormal hair coat, which may be long and wavy, fails to shed normally and is accompanied by excessive sweating and pruritus (itching).
  • Laminitis – increased digital pulse, pottery gait, standing with feet stretched out in front.
  • Excessive drinking and urination
  • Lethargy
  • Fat redistribution – a pot-bellied appearance, bulging above the eyes or ‘bags below the eyes’.
  • Other signs may include an increased susceptibility to infections, particularly of the skin and sinuses as well as foot abscesses.

How is it diagnosed?

There are several different blood tests that can be used to diagnose Cushing’s disease in the horse. One of the common tests is to measure the resting ACTH (adrenocorticotropin hormone). This is a simple once off blood sample that gives fairly reliable results in regards to diagnosis as well as being used to monitor the progression of the condition once treatment has started. Other blood tests include a Low Dose Dexamethasone Suppression Test and the ACTH stimulation test. Your veterinarian can offer advice on which test would be right for your horse.

Can it be treated?

Yes – there are drugs available to treat Cushing’s disease although there is individual variation in response to treatment.

The most commonly used drug is Pergolide, which is available either in tablet form or as a syrup – both of which are given daily by mouth. In response to this treatment horses typically become less lethargic, their coat condition improves and they often drink and urinate less frequently.

Like any older horse or pony, those with Cushing’s disease require a little extra TLC. Regular clipping of the coat helps with temperature regulation and may help relieve excessive sweating and itchiness. Ensure you keep up to date with foot trimming, routine dental care, vaccinations and worming. Any signs of infection should be treated promptly as horses often have a lower immune response and are less able to deal with even relatively minor infections.

If you suspect your horse may be suffering from Cushing’s disease please contact the team at SHEC or your local vet to organise a consultation.

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