Cushing's Disease in Dogs: Cause, Complications & Medications

Cushing's disease is a very serious condition that needs to be addressed as quickly as possible as it can cause potentially life-threatening illnesses. Today, our Oceanside vets explain the causes, symptoms, and treatment options for Cushing's disease in dogs.

Cushing's Disease in Dogs

Cushing's disease (hyperadrenocorticism) is a serious health condition that causes the adrenal glands to produce an excessive amount of cortisol (cortisone) in the body, which can leave a dog at risk for several serious conditions and illnesses ranging from diabetes to kidney damage. It can also be life-threatening. 

Also sometimes referred to as Cushing's syndrome, this condition is often caused by a benign or malignant tumor in the pituitary gland, a pea-sized gland located at the base of the brain. In some cases, the tumor may be located in the adrenal glands which sit just above the kidneys.

Excessive cortisol can also result from prolonged use of steroids, called iatrogenic Cushing's syndrome. 

What are the symptoms of Cushing's disease in dogs?

Common signs of Cushing's disease in dogs include:

You'll notice your dog displaying at least one of these symptoms if they have Cushing's disease. However, it's uncommon for all of these signs to be present. 

It's critical to contact your vet right away if your dog is displaying any of the symptoms listed above. Dogs with Cushing's disease have an increased risk of blood clots, high blood pressure, kidney damage, and diabetes. 

Diagnosing Cushing's Disease

Your veterinarian will perform a physical exam and run appropriate tests to determine the cause of your pet's symptoms and to rule out other health issues. These tests may include, but are not limited to, a complete blood panel, urine culture, urinalysis, and/or full chemistry panel. 

Your vet may order adrenal function tests, testing adrenal low dose and high dose dexamethasone suppression. That said, adrenal function tests can give false positives when another disease with similar clinical symptoms is present. 

An ultrasound may help to rule out other conditions that could potentially be causing your dog's symptoms. Other diseases that can cause similar symptoms to include bladder stones, gallbladder disease, chronic inflammatory liver disease, gastrointestinal disease, and tumors in the liver or spleen. 

Magnetic resonance imaging (MRI) allows your vet to examine your dog's adrenal glands, making it the most effective diagnostic test for Cushing's disease. However, this method of testing can be expensive.

At Oceanside Veterinary Hospital, our in-house diagnostics lab allows our vets to diagnose and treat a range of health conditions. We have access to diagnostic imaging tools and treatment methods to identify and manage these issues.

Treating Cushing’s Disease in Dogs

Cushing's disease in dogs is typically treated with medications that help decrease the amount of cortisone that the adrenal glands produce. The only way to cure Cushing's disease is to remove the tumor. However, because of the complexity and risks of surgery, most cases are treated with medication.

Treatments will vary depending on the type of Cushing’s disease your dog has.

Pituitary tumor. Treatment of pituitary-dependent Cushing’s disease is the most complicated. Two drugs, trilostane, and mitotane are commonly used. 

Adrenal tumor. Treatment of an adrenal-dependent Cushing’s disease usually requires major abdominal surgery. If the entire tumor can be removed and the tumor is not malignant, there is a good chance that your dog will regain normal health. 

Iatrogenic Cushing’s disease. Treatment requires gradual discontinuation of the steroid, usually resulting in a recurrence of the disease that was being treated by the steroid.  

After starting the medication treatments your dog will need to see the vet regularly for ACTH stimulation tests until the excessive production of cortisone is controlled.  

Over the lifetime of your pet, routine monitoring of blood tests and medication adjustments need to be made. 

The Fatality of Cushing's Disease in Dogs

The cause of your dog's Cushing's disease as well as the conditions your pup develops that are linked to the disease are going to impact your pet's prognosis. Early diagnosis and treatment are essential for limiting the severity of the disease.

The symptoms of Cushing’s disease can be minimized with diligent observation and long-term management. 

Most dogs can be successfully treated with few medication side effects. However, the wrong dose can cause mild or severe side effects. Therefore, your pet must be carefully monitored and follow-up blood tests are essential.

Dogs who do not receive adequate monitoring and follow-up often experience relapses and severe illness or death, as a result of complications.