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• Posted July 4, 2023

The Vet Says Your Dog Has Cushing's Disease: What Is It?

Like humans, older dogs can be prone to a variety of health issues.

Among the maladies that middle-aged and older dogs experience is Cushing's disease, when the body produces too much of a hormone called cortisol.

Fortunately, it is possible to test for and treat the condition, giving your pet a healthier late life.

"Cortisol is one of the body's natural steroids," said Dr. Ann Stohlman, a veterinarian in the Center for Veterinary Medicine at the U.S. Food and Drug Administration.

While a normal amount of cortisol helps the body adapt in times of stress, fight infections and maintain a proper body weight, too much weakens the immune system.

About 80% to 85% of Cushing's is triggered by a tumor on the pituitary, the pea-sized gland at the base of the brain.

A tumor can cause overproduction of adrenocorticotropic hormone (ACTH), stimulating the adrenal glands to make more than the body needs.

Cushing's disease can also be caused by a tumor in one or both adrenal glands.

Your vet can diagnose Cushing's with a blood test, which will also determine the type. They may also look for a tumor on an adrenal gland using an ultrasound.

Signs of Cushing's include increased thirst, appetite and urination; reduced activity; excessive panting; thin or fragile skin; hair loss; recurrent skin infections; and enlargement of the abdomen, giving a "pot-bellied" appearance.

If Cushing's is caused by an adrenal tumor, the only cure is to remove it.

"It's important for a veterinarian to see the dog regularly and do blood tests," Stohlman said. "Monitoring blood tests and response to treatment help determine the right dose, which may need to be adjusted periodically."

Watch this video for more on how to take care of a dog with Cushing's disease:

The medication Vetoryl (trilostane) is FDA-approved to treat both pituitary- and adrenal-dependent Cushing's in dogs. It works by stopping the production of cortisol in the adrenal glands.

Some dogs can't take Vetoryl, however, including those with kidney or liver disease; those who take certain heart medications; or those who are pregnant.

Side effects include poor or reduced appetite, vomiting, lack of energy, diarrhea and weakness. More serious side effects can include bloody diarrhea, collapse, severe sodium/potassium imbalance and destruction of the adrenal gland. This may result in death.

Another drug, Anipryl (selegiline), is FDA-approved to treat certain cases of Cushing's disease caused by a pituitary tumor.

Veterinarians have also used a chemotherapy drug approved for people called Lysodren (mitotane) as an “off-label” option.

"Treating Cushing's is a balancing act," Stohlman said. "But dogs with the disease can live a good life if they are monitored closely by a veterinarian and the owner is diligent about bringing the dog in for blood work and checkups, watching for side effects and giving the medication as directed."

Call your veterinarian right away if your dog is having a concerning side effect to any medication, the FDA recommended.

More information

The American Kennel Club has more on Cushing's disease in dogs.

SOURCE: U.S. Food and Drug Administration, consumer update, June 28, 2023