Introduction
Cushing’s disease is not a contagious illness and thus cannot be passed on to other horses and ponies. An endocrine disorder, Cushing’s disease can affect dogs as well as horses. Horses and ponies of all breeds can suffer from this disease. In severe cases of Cushing’s disease, and if there is no attempted treatment, fatalities can result.
Equine Cushing’s can also be known as ECD, pituitary adenoma and hyperadrenocorticism. The disease is caused by a series of changes which occurs in the affected animal’s brain due to hormonal problems. This disease is mainly caused by cortisone being overproduced from the adrenal gland. The enlargement of the pituitary gland is sometimes described as a tumour.
The pituitary gland found in the horse’s brain becomes overactive leading to hormonal changes, which in turn leads to the changes of the adrenal gland. Equine Cushing’s leads to the brain stem of the affected animal degenerating. Horses and ponies more susceptible to Cushing’s disease are usually more than fifteen years of age. Since ponies tend to live longer than horses, it is fair to deduce that a larger percentage of ponies end up being affected in contrast with horses.
The main signs and symptoms of Cushing’s in horses and ponies include a change in the affected animal’s coat. Due to its primary symptom it is known as Hirsutism or long-hair syndrome. The horse’s coat generally becomes longer and curlier. Humans can be affected by a human form of Cushing’s although transmission does not occur between the two. Therefore, there is no suggestion that this disease is zoonotic.
How can I tell if my horse has Cushing’s?
The characteristic clinical symptoms of Cushing’s disease are weight loss and the growth of a long, curly or wavy coat which is present all year round. The horse looks aged and many owners mistake this condition for simply the normal aging process of the affected animal. If a horse or pony is suffering from the disease, they are likely to have a fever, show signs of lethargy, drink more than normal and urinate excessively. Owners may notice that their horse is sweating more than usual, and have a reduced fertility level.
The disease progresses so that the immune system is lowered. As a result the affected horse becomes increasingly prone to problems such as laminitis and infections of the hoof, including painful abscesses. Pneumonia is also another infection affected horses become more at risk of. Proteins become more quickly metabolised which explains the weight loss of the horse. Oddly enough, it has been known for some horses affected with Cushing’s are actually overweight despite being placed on a strict diet. The skin may become dry or perhaps even greasy.
The horse might appear pot-bellied or have an uneven fat distribution. This can also occur around the eyes which give the horse a “goggle eyed” appearance. As the disease increases in severity, the brain becomes compressed by the ever increasing size of the pituitary gland. The horse becomes severely uncoordinated which can be distressing for both horse and owner. The animal may be drenched in sweat. The affected animal may begin to hyperventilate and become recumbent. It is possible for this to lead to the horse’s death.
Veterinary Diagnosis of Cushing’s Disease in Horses
Veterinarians may make an initial diagnosis by observing the signs and symptoms presents. In order to diagnose Cushing’s disease, blood and urine tests are required. However, these may need to be repeated as preliminary tests are not always conclusive.
Treatment of Equine Cushing’s Disease
There is no cure for the problem of the enlarged pituitary gland although there are treatments which are used to treat the symptoms presented by the disease. Pergolide mesylate is one of the medications which have been used in the treatment of the disease’s symptoms. It was originally used to treat human Parkinson’s and is given in tablet form which may be crushed into feed. Bromocriptine mesylate is less often used as it has been known to result in undesirable side effects. There have been suggestions that chaste berries can improve an affected horse’s condition and the positive results experienced are sometimes argued to prove its worth for horses with mild symptoms.
In very advanced cases it could be argued that there is no cure for Equine’s Cushing’s disease. These cases include those where the immunity of the horse has been so compromised by the disease that any medication may not have any effect. Despite this, there are sometimes long term measures which can be used in order to perhaps prolong the horse’s life and the increase the quality of said life.
Affected horses should be kept in an environment with minimal stress. This is due to the fact that affected animals are known to have higher stress levels than normal. This can be done by ensuring the horse is not place with aggressive field mates and by maintaining a scheduled regime. Horses should be rugged in cold weather and clipped in warm weather. It is essential that hooves are regularly trimmed. Due to their compromised immunity care should be taken by not allowing contact with new horses and, whilst maintain the necessary vaccinations, immunisations should be kept to a minimal degree. Careful worming and catching infections early is vital to keeping a horse suffering from the disease.
Prevention of Cushing’s Disease in Horses
Aside from minimising stress, there are very little suggestions on how to minimise the risk of a horse acquiring Cushing’s. Many horses, when they age can suffer from this condition and some may live on without being too badly affected by it.
Prognosis of Equine Cushing’s Disease
Horses suffering from Cushing’s that have been diagnosed in time can live for many years if they are successfully treated. Despite this, for those which have had their immunity compromised to such an extent the prognosis can be very poor. It has been known for horses to die from this condition if it is severe and if left untreated.
