What is "Cushing's Disease"?
The term "Cushing's disease" is borrowed from human medicine, and is another phrase for hyperadrenocorticism. This condition is caused by excess levels of the hormone cortisol in the body.
What is the hormone cortisol?
Cortisol is a hormone with several important functions. Among other things, it allows both humans and animals to cope with "stress." Cortisol is produced in two small organs in the abdomen called adrenal glands. The adrenal glands are under the direct control of a part of the brain called the pituitary gland. The pitutary gland signals the adrenal glands to make cortisol when it is needed, so the levels of hormone fluctuate throughout the day. The levels of cortisol are strictly controlled because too much or too little cortisol can be very harmful.
What causes Cushing's disease?
There are two types of Cushing's disease: either the pituitary gland is signaling the adrenal gland to make too much cortisol, or the adrenal gland is independently making too much cortisol. The majority of animals have a benign tumor of the pituitary gland that signlas the adrenals to make too much cortisol. In some animals, a tumor in one or both adrenal glands causes excess production. These tumors may be either malignant or benign.
What are the symptoms of Cushing's disease?
Cushing's disease usually occurs in middle-aged to older dogs and is extremely rare in cats. The most common clinical signs are increased appetite, excessive urination, excessive thirst, a pendulous abdomen, hair loss and weakness. Some cases, however, may not show any of these systemic signs.
How is Cushing's disease diagnosed?
Hormonal testing is required to confirm a diagnosis of Cushing's disease in a patient with symptoms suspicious of the disease. Once your pet has been confirmed to have Cushing's disease, additional tests may be necessary to determine which type they have, as the treatment and prognosis are different.
How is Cushing's disease treated?
Pituitary Dependent Cushing's disease can be controlled (not cured) with oral medication and periodic monitoring. Adrenal Dependent Cushing's disease is treated by surgically removing the tumor. Surgery is curative if the tumor is not malignant.
The majority of dogs with Pituitary Dependent Cushing's disease can lead a normal life with careful monitoring, and be successfully managed for many years.