A Suitable DietAll horses should be fed on a diet that ispredominantly, if not entirely, fibre. This isparticularly important in horses or ponies withCushing’s Disease because of the increasedrisk of laminitis. A feed balancer may be usedto ensure that the horse is getting all of thenutrients it requires.

It is also key that animals with Cushing’sDisease are not allowed to become overweightand their body condition should be monitoredclosely. More detailed advice can be found inthe BHS leaflet ‘Advice on Basic Feeding’.

Farriery and Foot CareAll horses should receive regular attention froma qualified farrier, even if they remain unshod.The requirements of each horse will vary, butas a guide, the feet will need to be seen at leastevery four to eight weeks.

Foot care is of particular importance in horsesthat have suffered from laminitis and thus mustbe seen as a priority for animals with Cushing’sDisease.

Cushing’s Disease

ADVICE ON

Cushing’s Disease

Other Useful BHS Leaflets:Advice on Basic FeedingAdvice on Essential Health CareAdvice on LaminitisAdvice on Worm Control

Welfare DepartmentThe British Horse SocietyAbbey ParkStaretonKenilworthWarwickshire CV8 2XZCall: 02476 840517Fax: 02476 840501www.bhs.org.ukEmail: welfare@bhs.org.uk

© The British Horse Society Welfare Department 2011Registered Charity Nos. 201504 and SC038516

Coat CareThe hirsutism that causes many horses withCushing’s Disease to develop an abnormalcoat means that affected horses may need

clipping even during the summer months toensure that they are comfortable.

Extra attention should also be paid togrooming to avoid the coat becoming matted.

Health MonitoringAs Cushing’s Disease can lead to a decreasedfunctioning of the immune system, it isimportant to keep an eye on affected horses tospot any potential signs of infection. Likewise,it is important to check the horse regularly andthoroughly for cuts or wounds that maybecome infected.

Prompt attention and treatment, including froma veterinary surgeon if necessary, can preventor minimise an infection that could otherwiseprove extremely dangerous to a horse withCushing’s Disease.

As with any older horse, horses withCushing’s Disease should receive regularattention (ideally every six months) from aBAEDT accredited dental technician.

This leaflet is produced with the support ofBoehringer Ingelheim VetmedicaEllesfield AvenueBracknellBerkshire RG12 8YS

Cushings Disease leaflet_Layout 1 23/08/2011 12:09 Page 1

Equine Cushing’s Disease, also known as Pituitary Pars Intermedia Dysfunction (PPID), is a chronic,progressive condition and is the most common endocrine (hormone) disorder of older horses1.Thanks to advances in husbandry and veterinary care, horses and ponies are now living for longerthan ever before, meaning that Cushing’s is becoming an increasingly prevalent disease as itmainly affects older animals. Any breed or type of horse or pony may develop Cushing’s Disease,although it does seem to affect ponies more frequently than horses. Some estimates suggest thatmore than 15 percent of horses and ponies above 15 years of age are affected2.

The pituitary gland is a small pea-sized gland located at the base of the brain. The gland is cruciallyimportant in controlling a range of functions including metabolism, reproduction, growth andlactation. In horses and ponies suffering from Cushing’s, age-related degeneration means that animbalance occurs in the hormones secreted from the pituitary gland, which in turn imbalances thesecretion of other hormones produced in the body. It is the consequences of these hormonalchanges which result in the clinical signs of Cushing’s Disease.

While Cushing’s is more common in older horses and ponies, many are still enjoying active lifestyleswhen the disease is diagnosed.

Horses also lose muscle condition and candevelop a pot bellied appearance, potentiallyaccompanied by a sunken back andprotruding spine. Sometimes an abnormaldeposit of fat above the eye may be seenwhere a horse would normally have adepression.

As the changes are often subtle and notassociated with a particular condition, many

early cases are not seen by a veterinarysurgeon and remain undiagnosed. It is alsoworth noting that some signs, for exampleincreased drinking and urination, are easier tospot in a stable kept horse than one that livesout permanently. It is general good practice tomonitor the feed and water intake, andurination/defecation patterns of any horse inorder to be alert to any abnormalities.

Clinical SignsNew research suggests that more than 80 percentof horses suffering from laminitis may have anunderlying endocrine disorder like Cushing’sDisease3, and recurring bouts of laminitis andhirsutism (abnormal coat) are two of the mostcommon clinical signs of the condition (see the BHSleaflet ‘Advice on Laminitis’ for more information).Hirsutism can range from mild changes in coatshedding right through to a full, long, curly,overgrown coat. In some cases, horses may notmoult in the spring and there are often variationsin the shedding – for example, a horse may notcompletely moult. The picture on the cover of thisleaflet shows a pony with particularly extremehirsutism. Not all horses will be affected to thisextent.Not all horses will display the same clinical signs.Other signs, which are often variable and notspecific to Cushing’s, may include:

• excessive sweating• increased appetite• increased drinking and urination• lethargy• poor performance• reduced immune function; this can result in

recurring skin and respiratory infectionsincluding sinusitis, dental disease and anincreased susceptibility to worms.

Effective WormingAn effective worming programme is essential because Cushing’s Disease may cause suppressionof the immune system. Regular faecal egg counts can be used to determine the frequency withwhich wormers should be given and your veterinary surgeon will be able to advise on the mostsuitable worm control programme for your horse. The BHS leaflet ‘Advice on Worm Control’ isanother useful source of information.

Cushing’s Disease Cushing’s Disease Cushing’s Disease

The hypothalamus (section of the brainlocated next to the pituitary gland) andthe anterior lobe of the pituitary gland

References1 Donaldson et al. “Evaluation of suspected pituitary pars

intermedia dysfunction in horses with laminitis”. JAVMA, Vol224, No. 7, 1 April 2004

2 McGowan. “Diagnostic and Management Protocols for EquineCushings Syndrome” In Practice, November/December 2003

3 McGowan. “Epidemiology and Clinical Perspectives ofEndocrinopathic Laminitis”, BEVA Congress 2009

DiagnosisEarly diagnosis and treatment of horses andponies affected by Cushing’s Disease gives thechance for treatment to deliver the bestoutcome. However, the initial stages of thecondition are often slow to appear and difficultto detect, resulting in a delay before diagnosisand treatment.

A blood test is needed to confirm the diagnosiswhich can be carried out by your vet. However,many horses with clinical signs, includingrecurrent laminitis, still go undiagnosed –which makes the awareness of horse andpony owners about the disease critical to earlydetection.

A pony with an abnormal fat deposit above its eye.Picture courtesy of Liphook Equine Hospital

Treatment andManagementTreatment of affected horses and poniescentres on dealing with any immediatemedical problems (for example, laminitis casesgenerally require a combination of pain relief,foot care and so on), together with addressingthe underlying endocrine imbalance.

While there is no cure for Cushing’s, an effectivelicensed medicine is now available fromveterinary surgeons which helps normalise thehormone secretion of affected horses and

ponies, and in so doing reduces clinical signsassociated with the disease. Although theresponse to this treatment may vary withdifferent horses, there have been someexcellent results achieved.

As most horses and ponies with Cushing’sDisease are above 15 years of age, many maybe suffering with other conditions associatedwith increasing age, as well as clinical signs ofthe disease. It is therefore important to have agood programme of routine preventativehealthcare, particularly as the immune systemmay not be working as well in some of thesehorses. This should include:

A horse before and aftertreatment of Cushing’sDisease

The hypothalamus and the anterior lobe of thepituitary gland which is divided into three parts –pars intermedia, pars distalis and pars tuberalis

Cushings Disease leaflet_Layout 1 23/08/2011 12:09 Page 2