Cushing’s Disease and Your Dog

The diagnosis of Cushing’s disease may start as vague sense that all is not right with your dog. He may tire easily after exertion or have a “pot-bellied” appearance. The first systems of Cushing’s can be unspecific or similar to other health problems. Over time, however, the cortisol levels in your dog’s body can cause increasing problems unless properly treated by your veterinarian.


What Is Cushing’s Disease?

Cushing’s disease is a condition in which the glands of the dog’s body produce too much of a hormone called ACTH that produces cortisol. Sometimes, a microscopic tumor on the pituitary gland causes this overproduction of the hormone. Other times, tumors can grow on the adrenal glands, which can also cause excess amounts of cortisol to be produced. Excess cortisol may also be caused by glucocorticoid medications given to dogs to treat allergies. Cushing’s disease generally affects dogs over the age of 5 years.

Symptoms of Cushing’s Disease

Cushing’s disease symptoms can range from the very subtle to the dramatic. Increased thirst and urination may be the first symptoms noticed. The dog may have increasing accidents in the house due to the increased water consumption. The dog’s hair may fall out generally in a widespread manner rather than in clumps. The dog may pant excessively. This symptom is somewhat subjective and is unreliable in diagnosing Cushing’s. The dog’s skin may become thinner. This thinning can also occur with aging, so it is not always a good way to determine Cushing’s disease. Increased appetite, often to an extreme degree, is another symptom of appetite. This symptom can be related to the enlarged abdomen of the Cushing’s sufferer. Cushing’s disease causes fat to be re-distributed to the abdomen, as well as causing enlargement of the liver. The pot-belly can be very prominent as the disease progresses. Weakening of the heart and muscles of the body also occurs in Cushing’s disease. A previously active dog may show no interest in exercise. Calcified skin lumps, called calcinosis cutis, may also occur. Though these symptoms can be helpful in making the diagnosis of Cushing’s disease, the definitive diagnosis is generally done by laboratory blood testing that can determine increased liver enzymes, decreased kidney function and increase alkaline phosphate levels. Abdominal ultrasound and low dose dexamethasone suppression tests can also be helpful for diagnosis.

Breeds Susceptible to Cushing’s Disease

Though Cushing’s disease can affect any breed of dog, some breeds appear to be more susceptible to the disease. Boxers, Boston terriers, poodles, miniature schnauzers, dachshunds and German sherherds are all associated with increased rates of Cushing’s disease. Cushing’s generally occurs in middle-aged to older animals.

How Is Cushing’s Treated?

A number of medications are available for canine Cushing’s disease. These mediations often require frequent blood testing to determine levels in the body.  Lysodren, also called mitotane, is a drug used for human cancers that is used off-label to treat Cushing’s disease in dogs. It essentially kills the adrenal gland that overproduces the cortisol. Dogs on Lysodren must be carefully monitored to prevent negative side effects. Vetoryl, also called trilostane, stops the production of cortisol in the adrenal glands. Anipryl, generic name selegiline, is used to treat Cushing’s disease that originates in the pituitary gland. Surgery to remove tumors from the adrenal gland that cause excessive cortisol production is sometimes done but can entail significant risk to the animal.

Prognosis For Cushing’s Disease

Fortunately, Cushing’s disease is not a painful condition and dogs can live comfortably for many years if the disease is managed. If no treatment is given for Cushing’s disease, it will progress to heart, liver, kidney, pancreas and neurological problems. The rate of decline can be unpredictable. With good treatment, you dog can live for many years enjoying normal activities.