Equine Cushings Disease

What is Equine Cushings Disease?

Equine cushings disease is known scientifically as Pars Pituitary Intermedia Disorder (PPID), an endocrine disease that can occur in 20% of horses, ponies and donkeys. The disease is far more prevalent in horses over the age of 15 and although not impossible, it is rare for horses to develop PPID under the age of 10.

Why does PPID develop and what clinical signs develop?

PPID can develop due to enlargement of the pituitary gland located at the base of the brain. This can result in dysregulation of hormone production. The key hormone in PPID is called ACTH. When too much ACTH is produced, there in an increase in the hormone called cortisol. This can result in many changes within the body and can range from subtle signs to obvious signs in more prolonged cases.

Clinical signs can consist of any of the following, either individually or in combination:

• Laminitis: acute or chronic, may be long term with no other signs
• Long, curly haircoat
• Abnormal sweating
• Delayed/ abnormal coat moulting
• Increased/ excessive drinking and/or urination
• Lethargy/ dull demeanour
• Abnormal body shape: muscle loss, “pot belly”, abnormal fat distribution
• Increased susceptibility to infections: skin infections, foot abscess, dental infections

How is PPID diagnosed?

PPID can be diagnosed by clinical signs alone in some cases, however in most cases it is necessary to confirm the diagnosis with a blood test. It is recommended to blood test before treatment is started to gain an idea of hormone levels, so an effective monitoring and medication dosage can be achieved. The blood test used is to measure the level of the hormone ACTH in the horses blood.

Can PPID be treated?

There is no cure for PPID. Most horses and ponies can be successfully managed with PPID using a combination of medication and good management and regularly blood tests are recommended. 

Useful management changes include:

• Good quality fibre based diet and regular weight monitoring
• Good preventative healthcare. Routine dentistry, vaccinations, worming.
• Routine farriery to minimise feet problems, and monitor for signs of laminitis

What is the long-term outlook?

Most horses will respond well to treatment and management changes. Horses with severe cases of laminitis can be difficult to control, even if the PPID is controlled well.