Cushings Disease in horses and ponies - Symptoms & Treatment

The definition of Equine Cushings Disease (also known as Cushing's Syndrome) is an abnormality of the endocrine, or the hormonal system of the horse's body.

A horse or pony that has cushings will typically have the appearance of a horse that is old before its time - a dull thin horse or pony with a shaggy matted coat, feet in poor condition, sore patches of skin and mucky eyes.

Of course these symptoms can appear through neglect, starvation or cruelty - but we now know that these signs can arise in middle aged horses which are well cared for as a result of cushings disease.

How to recognise Cushing's Disease in Horses

The clinical signs and symptoms of this hormonal upset are quite characteristic and are all caused by changes in the hormones of the horse affected by Cushing's Disease.

Changes in the Coat

This is often the most noticeable feature of the "Cushings" horse. The hair of the coat becomes long and curly, especially over the flank and quarters.
 

Dullness

The general demeanour and brightness of the horse fades - the horse or pony appears old and slow.
 

Increased thirst and urine production

Affected horses often drink excessively.
 

Mucky and sometimes bulging eyes

Horses with Cushing's Syndrome will sometimes have abnormal deposits of fat, especially around the eyes. This can make the face look a little "goggle eyed". It can also interfere with the drainage of tears - so that the eyes are permanently mucky.
 

Laminitis

Many horses with Cushings suffer from Laminitis which is not due to over feeding or gorging on grass. The cause seems to be an increased level of cortisol from the adrenal glands - it is recognised that treatment with injections of cortisone can induce Laminitis. There is usually no response to dietary and managemental changes.

Causes of Cushing's Disease in Horses

Within the horse's body several of the key hormonal glands, for example the thyroid and adrenal glands, are controlled the Pituitary gland - which is situated within the horse's head.

The pituitary gland is a small pea sized extension of the horse's brain. Because it is connected with the brain, normal pituitary function is influenced by nerve impulses from all parts of the brain.

When a horse or pony sees or hears something which frightens it the sense of fear is sent to the pituitary - which releases a hormone to activate the adrenal glands.

In cases of Cushing's Disease the pituitary gland slowly starts to lose control of the other glands in the horse's body.

This is usually because of the presence of one or more small tumours within the pituitary gland which secrete controlling hormones in an increased and haphazard way.

The result is that glands which depend on the pituitary for control are bombarded with excess control hormones and they then produce too many of their own particular hormones.