What Is Cushings Disease in Dogs?

The Signs to Look for, Diagnosis and Treatment

Does your older dog suddenly have to urinate more than usual? Is he eating you out of house and home? Do you have to fill his water bowl more often? These may not be signs of growing older; they may indicate your dog has Cushing’s disease (hyperadrenocorticism), a chronic, but treatable condition.

Cushing’s disease affects the adrenal glands, which are near the kidneys and produce cortin. Cortin regulates many important body functions, including body weight, mineral balance, connective tissue structure, white blood cell production and skin condition. The pituitary gland, which is at the base of the brain, stimulates the adrenal glands with a hormone ACTH to produce cortin. Either a benign, although sometimes malignant, tumor on the pituitary gland or on the adrenal glands causes Cushing's. The tumor may be benign, but the disease can be life-threatening if left untreated.

Other Symptoms
Cushing’s has many symptoms, some that can be mistakenly attributed to old age and some that are clear signs that something’s wrong.

Increased appetite
Increased urination
Increased consumption of water
Fur loss
Swollen abdomen
Thin skin

A complete blood panel will confirm whether the dog has Cushing’s or not. Further tests will reveal whether the tumor is on the pituitary or the adrenal glands. One of these tests is a urinalysis to test the cortisol (one of the regulatory hormones produced by the adrenal glands) and creatinine levels. This alone is not sufficient to diagnose Cushing’s since elevated creatinine can indicate kidney disease. Another is an ultrasound of the abdomen to see if the tumor is on the adrenal glands. If it is, the affected gland will be very large or uneven. If it’s not found there, then the tumor is on the pituitary gland. Usually, the tumor is on the pituitary gland.

If the tumor is on the adrenal glands and the vet indicates an operation is a good idea, then all symptoms will disappear once the vet removes the tumor. This is a delicate operation, and often enough the vet decides not to operate, but to use the medications.

If the tumor is on the pituitary, it isn’t operable. The treatment for the adrenal tumor works on the pituitary tumor also. There are several medications, but all have side effects, so the vet must monitor the dog carefully. The medications are Lysodren, Nizoral (used infrequently now), Anipryl and Vetoryl.

As your dog ages, you have to watch the dog carefully for any changes in behavior. They may be ordinary signs of aging, but then again they may signal health problems, such as Cushing’s, which require immediate medical attention.