Causes of Cushing’s Disease in Cats
Cushing's disease, also known as hyperadrenocorticism, is a disorder that involves excessive production and secretion of steroid hormones by the adrenal glands. In the vast majority of cases, Cushing’s in cats involves excess production of cortisol. Unlike Cushing’s disease in dogs, this disease in cats is closely associated with diabetes mellitus. Cushing’s can be either pituitary-dependent (caused by a pituitary gland tumor) or caused by a tumor in one or both of the cat’s adrenal glands. It is uncommon for Cushing’s disease in cats to be caused by iatrogenic administration of steroid drugs. Most affected cats have pituitary gland tumors; those with adrenal gland tumors usually have either benign adenomas or malignant adenocarcinomas, with roughly equal distribution. Cats with pituitary-dependent hyperadrenocorticism produce and secrete too much adrenocorticotropic hormone (ACTH) from their pituitary gland. This over-stimulates the adrenal glands and causes them to secrete excessive amounts of cortisol and other adrenal hormones. It also causes the adrenal glands to become enlarged, which is known as adrenal hypertrophy. Cats that have functional adrenal gland tumors, without pituitary gland involvement, produce and secrete excessive amounts of cortisol autonomously.
Preventing Cushing’s Disease in Cats
There is no reliable way to prevent Cushing’s disease in domestic cats. Until medical science figures out what causes Cushing’s disease, it will continue to occur in cats and other companion animals. The best we can do is manage the disorder and try to keep affected cats as comfortable as possible.
Fortunately, Cushing’s disease is uncommon in cats, although it is fairly common in companion dogs. Treating this disease involves reducing or preventing the excessive production of steroids by the adrenal glands. Those glands can be removed surgically, which usually is quite successful in resolving a cat’s symptoms of Cushing’s disease. A number of drugs are also available to either inactivate the adrenal glands or otherwise regulate and normalize the amount of steroid hormones that they produce.