December 18, 2019 Dogs Internal Medicine

Addison’s Disease in Dogs: What is it and can it be prevented?

A small white poodle sitting on a couch in the sun

Addison’s Disease in Dogs: What is it and can it be prevented?

I have Addison’s disease on my mind. Earlier this month, I was a guest on SiriusXM’s Doctor Radio Channel 110 with Dr. Frank Adams from NYU-Langone Medical Center. One of the callers asked a question about Addison’s disease in their Italian greyhound. Then, in the clinic, one of my favorite patients, a flashy white poodle with Addison’s disease was in for a checkup. Finally, a husky, with abnormal sodium and potassium levels in the blood was admitted to the emergency service with a working diagnosis of Addison’s disease. No wonder this disease is on my mind!

Defining Addison’s Disease

Addison’s disease, or hypoadrenocorticism, named after Thomas Addison, a Scottish physician who first described the disease in 1855, is the underproduction of hormones from the adrenal gland. The deficient hormones control blood levels of sodium and potassium and the body’s ability to respond to stress. Addison’s disease in the dog was first described a century after the disorder was reported in humans. Dogs with Addison’s disease can have low blood sugar and severe dehydration exacerbated by vomiting and diarrhea. Response to treatment is excellent, but lifelong management is required.

Preventing Addison’s disease

The SiriusXM caller wanted to know if he could have done something to prevent the Addison’s disease in his dog. The short answer is no; but there are important details here. In dogs, Addison’s disease occurs when the adrenal glands are destroyed by the dog’s own immune system. Certain breeds are predisposed to the disorder, including the Portuguese water dog, standard poodle, bearded collie, cairn terrier, cocker spaniel and the Nova Scotia duck tolling retriever. Genetic studies of these breeds are beginning to pay off, identifying a possible genetic source of the disease. We also know that female dogs are at greater risk for developing Addison’s disease. As of right now, we can’t prevent this disease because we can’t change your dog’s sex, breed or immune system, but hopefully in the future we’ll have the tools to put this promising research to preventative use.

Managing Addison’s Disease

My patient Bo is a classic case of Addison’s disease: a young female, standard poodle. She gets two kinds of pills daily: one to control her sodium and potassium and the other to replace her stress hormones. Usually veterinarians choose monthly injections to control Addison’s disease, but Bo responded poorly to this treatment. During her routine checks, I draw blood to test her sodium and potassium to help me adjust medications. When Bo goes to the beauty parlor, she gets an extra dose of prednisone (the stress-regulating hormone) to compensate for her excitement at being beautified!

False Addison’s Disease

The husky admitted to the AMC’s emergency service had one of my favorite diseases, false Addison’s disease, or pseudohypoadrenocorticism. This poor fellow had lost weight, had terrible diarrhea and abnormalities in blood sodium and potassium levels. However, the veterinarians in the ER looked at a stool sample and found whipworms, which were causing the Addison’s disease-like warning signs. Crazy as it sounds, whipworms in the intestine can cause sodium and potassium abnormalities in the blood. How this happens is unclear. Adrenal gland hormones appear normal in dogs with pseudohypoadrenocorticism from whipworms. The reason I love this disease it is 100% curable by deworming.

I hope your dog never develops Addison’s disease, but now you can see why I have this interesting disorder on my mind.