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