Cushing’s disease is a tumour in the pituitary gland that grows and sends inappropriate signals to the body to secrete excessive hormones, primarily encouraging the secretion of the stress hormone cortisol.  Too much cortisol can have a negative effect on the body in numerous ways.

Cushing’s disease can not be cured but it can be managed and controlled. All breeds and types of horses can be affected by Cushing’s but it is common in pony breeds.  It is also quite common in older horses over the age of 15. 

Symptoms of Cushing’s include:

• A long and uneven coat that fails to shed normally
• Weight loss – despite a normal or even an increased appetite
• Lethargy, acting docile and being more tolerant of pain
• Loss of muscle mass – particularly in rump and saddle areas
• The appearance of a pot belly and fat deposited along the neck, above the tail and above and behind the eyes.
• Sweating – particularly in those with long coats
• Drinking an excessive amount of water
• Urinating excessively
• Recurrent infections – especially dental and respiratory
• Ulcers in the mouth
• Wounds taking an unusually long time to heal
• Unexplained and recurrent laminitis
• Susceptibility to worms.

Cushing’s can be confirmed by a blood test where the vet will possibly try to rule out other diseases first. Medical treatment is available for Cushing’s but is expensive and once started, it must be maintained throughout the life of the horse.  Medication can very quickly show an improvement in the coat of the horse and a reduction in drinking and urination.  It will lessen the symptoms overall and improve their quality of life.

Although Cushing’s is incurable, management of an affected horse is exceedingly important:

• Horses with long coats would benefit from regular clipping due to the excessive sweating.
• Regular dental care is important
• Weight should be carefully monitored
• Routine foot care and regular visits to the farrier should take place.
• Prompt treatment of infections is recommended
• Vaccinations and worming are more important than usual and should be kept scrupulously up to date. 

If you are worried that your horse may have Cushing’s then it is important to consult your vet.