| Cushing's disease occurs in various animals (e.g. dogs, | | | | may notice an abnormal amount of urine (or soiled |
| horses, people), although the symptoms in horses are | | | | bedding) in its box. |
| different than the symptoms in other animals (e.g. in | | | | - Development of laminitis. The most common cause |
| dogs it results in hair loss whereas in horses it results | | | | of normal laminitis is carbohydrate overload due to |
| in greater hair growth). When the disease occurs in | | | | eating spring grass, whereas ECD-caused laminitis is |
| horses, it is known as Equine Cushings Disease (or | | | | more frequent in autumn and winter since ECD is |
| ECD). | | | | worse when the days are shorter (this is because |
| ECD is an illness caused by excessive hormone | | | | the pineal gland is light-sensitive and as daylight |
| production. The pituitary gland produces too much | | | | decreases it stimulates the pituitary gland). |
| hormone, which over-stimulates the adrenal glands, | | | | - Immune system declines, leaving the horse more |
| which in turn produce too much steroids. It is the | | | | prone to infections and slower to heal from external |
| excessive quantity of steroids which causes the | | | | injuries. |
| symptoms associated with ECD. The over-production | | | | - The depressions above the eyes fill in. These |
| of the pituitary can be caused various changes, such | | | | depressions are most evident when a horse is |
| as the growth of benign tumors, enlargement of the | | | | chewing, but gradually fill in with fat in ECD horses. |
| pituitary due to age-related changes, or a decline in | | | | Any of these symptoms can be caused by a variety |
| the regulatory chemical dopamine due to age-related | | | | of illnesses other than ECD. Consequently, blood and |
| changes in the brain. All of these factors tend to be | | | | urine tests are normally used to confirm that the |
| age related, so the disease is much more common in | | | | cause is ECD (e.g. by measuring hormone levels and |
| older horses (over 15 years) although it has been | | | | hormone response levels) and to rule out other |
| found in horses as young as seven years. | | | | possible diseases. Studies have shown that many |
| The nature and cause of the disease itself was first | | | | horses with ECD are either not diagnosed or |
| explained by Harvey Cushing, an American brain | | | | incorrectly diagnosed (the symptoms are incorrectly |
| surgeon, in 1921. Consequently, the disease is named | | | | attributed to a different disease), with the result that |
| after him. | | | | they do not receive appropriate treatment. |
| Symptoms and Diagnosis | | | | Treatment |
| The symptoms of cushings disease vary somewhat | | | | ECD cannot be cured. However, the hormone levels |
| from horse to horse, with the more common | | | | can be reduced to more normal levels through |
| symptoms including: | | | | medication, slowing the progress of the disease. As |
| - Changes to the coat. It may become longer and | | | | some of the medications can have serious side |
| curly. It may not be shed in Spring. In some cases | | | | effects (e.g. liver disease), one needs to monitor for |
| the color becomes lighter. | | | | any such side effects and change the medication |
| - Increased sweating. This is often due to the coat | | | | accordingly. |
| become longer and thicker, and retention of the | | | | As cushings disease can result in the development of |
| winter coat into summer. | | | | secondary diseases (e.g. laminitis, diabetes), the horse |
| - Weight loss despite increased appetite and food | | | | needs to be closely monitored for any symptoms of |
| consumption. Changes to the body shape, with loss | | | | these, with appropriate and prompt treatment. |
| of muscle in back and neck, and development of | | | | Management of the symptoms can make the horse |
| pendulous abdomen. | | | | more comfortable and increase its quality of life. For |
| - General depression, loss of coat shine, horse looks ill. | | | | example, if the horse cannot shed its winter fur and |
| Development of diabetes and a resulting increase in | | | | consequently over-heats in summer, the coat should |
| water consumption. This can be difficult to detect | | | | be clipped. |
| with pastured horses, but with stabled horses one | | | | |