Ask the expert Equine

STUDIES SHOW THAT HORSES DEVELOP EQUINE CUSHING’S DISEASE ANY TIME AFTER THE AGE OF 10, WHICH MEANS THAT MANY DRESSAGE HORSES PERFORMING TODAY COULD BE AT RISK OF THIS POTENTIALLY DEBILITATING CONDITION. DR MARCUS BENNETT MRCVS ADDRESSES THE IMPORTANCE OF SPOTTING THE SIGNS OF THE DISEASE EARLY, AND WHAT YOU CAN DO IF YOU SUSPECT YOUR HORSE MAY BE SHOWING SYMPTOMS.

QWhat causes Equine Cushing’s

Equine Cushing’s disease – or more correctly termed Pituitary Pars Intermedia Dysfunction (PPID) – can occur in any horse or pony. It occurs when the control mechanism for the pituitary gland fails, and the gland produces abnormally high hormone levels (see diagram below). There is no gender or breed disposition, but it does become more common with age.

NORMAL DOPAMINE PRODUCED BY THE HYPOTHALMUS REGULATES THE PITUITARY GLAND

NORMAL HORMONE PRODUCTION BY PITUATARY GLAND REDUCED DOPAMINE PRODUCED BY THE HYPOTHALMUS SO PITUITARY GLAND ACTIVITY IS UNCONTROLLED

INCREASED HORMONE PRODUCTION BY OVERACTIVE PITUATARY GLAND

QWhat are the tell-tale signs to

Laminitis is the most life-threatening symptom caused by Cushing’s disease. Although the severe signs of laminitis are well recognised, research shows that the early and moderate signs are still under-recognised. One of the early signs of laminitis can be divergent hoof rings; this is where the hoof rings are closer together at the toe than at the heels. An easy-to-follow checklist which may help you pick up the early signs of laminitis in your horse can be downloaded from CareAboutCushings.com/how-to-spot-it

Equine Cushing’s disease is known to cause lethargy which can manifest itself in several ways. In dressage this symptom could be seen as a lack-lustre performance, or reduced impulsion.

Equine Cushing’s disease can cause muscle wastage and changes in where fat is deposited. These changes will have a gradual onset and can include the development of a pot belly or cresty neck, loss of topline, a dimpled appearance to the muscle over the rump, and the development of fat pads over the eye area.

In addition to this, Equine Cushing’s disease can cause unusual sweat patterns and coat changes such as a late or partial shed, or the appearance of long guard hairs on the belly.

Increased drinking and urination can indicate the presence of Cushing’s disease, and this is most commonly noticed by owners when the amount of wet bedding increases, their horses are spotted drinking from unusual containers or their horse’s water trough is needing to be re lled ore fre uently

Struggling to get an infection under control (e.g. a high worm burden, a foot abscess, a corneal ulcer or mud fever) can be a sign of Cushing’s. This is because Equine Cushing’s disease is known to suppress the immune syste a ing it ore di cult for t e orse to g t o infections

It’s also important to recognise that many of the symptoms of Cushing’s can have a slow and insidious onset and can sometimes be confused with the signs of aging. This is

a particular challenge because Cushing’s disease is generally seen in horses and ponies over the age of 10, with occurrence increasing to 1 in 5 horses over the age of 15.1

If you identify any signs of Cushing’s you should ask your vet to examine your horse. If they feel that a test for Equine Cushing’s disease is appropriate they may be able to provide you with a free diagnostic test through the Care About Cushing’s programme (careaboutcushings.co.uk).

In order to carry out this test your vet will take a simple blood sample to look for an increase in the levels of a hormone called e els of naturally fluctuate with a peak in autumn, making this an ideal time to have your horse tested as the test is more likely to correctly identify the presence of Equine Cushing’s disease between July and October.

QIs a diagnosis of Equine Cushing’s

Fortunately, this diagnosis does not mean an end to your horse’s activity. If your horse is diagnosed with Equine Cushing’s disease

For more information about Equine Cushing’s diesease visit CareAboutCushings.co.uk where there are helpful articles to guide you with nutrition, care and monitoring of your horse. If your horse is receiving treatment for Equine Cushing’s Disease you may be eligible for a FREE* annual monitoring test: visit careaboutcushings.co.uk to find out more.

*Free basal ACTH laboratory fees only. Visit, blood sampling and interpretation fees may be applied by veterinary practices.

to then maintain an appropriate condition for their level of work. You can download a leaflet discussing t e nutritional requirements of horses with Cushing’s from the resource section of careaboutcushings .co.uk there are two key things that you can do to Exercise plays an important role in minimise the impact of this disease on their maintaining muscle mass and keeping your quality of life. orse t s us ing s can cause c anges in e rst is to treat t e disease it a condition, it is worthwhile ensuring that your licensed medication. This will be in the form orse s saddle tting is c ec ed regularly and of a daily tablet prescribed by your vet, and especially after any changes in body shape. regular six-monthly check-ups and blood Cushing’s disease can predispose horses to tests to check that the dose of this medication dental issues, such as sinusitis or tooth root is appropriate for your horse. infections. Regular maintenance is vital to

FEI and BD rules state that a horse address any issues early. cannot compete whilst receiving Pergolide, References: a treatment for Equine Cushing’s disease, so 1. McGowan, T.W., et al. (2013) ‘Prevalence, risk factors and it is a good idea to discuss your individual clinical signs predictive for equine pituitary pars intermedia situation with your vet. 2. dysfunction in aged horses’. Equine Vet J 45, pp. 74–79. Tatum, R.C., et al (2020) ‘A cross-sectional study of horses

The second is to produce and stick to diagnosed with pituitary pars intermedia dysfunction in the a plan to manage their nutrition, exercise United Kingdom: Treatment practices and factors associated and healthcare. with quality of life’. Global Equine Endocrine Symposium Proceedings, p. 39.

Nutritional support and regular measurements of body condition or fat score will allow your horse to regain any condition lost as a result of Cushing’s, and