Cushing’s disease, or hyperadrenocorticism, is caused by a hyperactive adrenal gland or tumor of the adrenal or pituitary gland. The disease affects humans, as well as dogs, cats, horses, and other animals, but dogs are most often affected by the condition. Cushing’s disease tends to occur in dogs older than six years, but pets of all ages can develop the disease.
Without treatment, Cushing’s can cause symptoms severe enough to interfere with activity and quality of life. Consult your veterinarian if you believe your pet may be suffering from Cushing’s disease. Symptoms of Cushing’s disease Symptoms of the disease vary widely and depend on which hormones are overproduced by the adrenal glands.
Most commonly, Cushing’s causes an overproduction of glucocorticoids, which are steroid hormones. Dogs dealing with excess glucocorticoid production may appear potbellied, have thin legs and weak muscles, and drink and urinate more than average. These dogs may also be more prone to infections than other dogs as overproduction of glucocorticoids suppresses the immune system. Other symptoms of Cushing’s disease include diarrhea, vomiting, hair loss, thin skin, reduced activity, panting, increased appetite, high blood pressure, and calcified lumps beneath the skin. Cats with Cushing’s disease may experience diarrhea, curled ear tips, weakness, fragile skin, enlarged liver, symmetrical hair loss, enlargement of the abdomen, and changes in weight.
Excessive eating, drinking, and urination is also possible in cats, as is an unkempt appearance. Diagnosis and Treatment, Unfortunately, there is no single test to identify Cushing’s disease. This makes the disease difficult to diagnose. Blood and urine testing may show abnormal results, and ultrasound examination and x-rays can detect the presence of an adrenal or pituitary tumor. X-rays may also show liver enlargement, which is common in Cushing’s disease.
Treatment is with medication or surgery, depending on the underlying cause of the disease and the severity of symptoms. If a tumor is present, surgical removal of the mass may eliminate symptoms. In some cases, medication may be used in lieu of surgery to manage cases associated with a tumor because surgical removal of adrenal tumors is very risky, and pituitary tumors are rarely treatable with surgery. Medication is effective at slowing hormone production in the absence of a tumor.
Although untreated Cushing’s disease is not usually fatal, it can weaken the immune system and make animals considerably more vulnerable to potentially serious infections and diseases. It can also cause severe weakness, fatigue, and exercise intolerance, which in turn significantly decreases quality of life and may lead to obesity and related health complications.