Cushing’s Disease in Dogs: What Pet Owners Should Know

Dr. Zeke Zekoff
Apr 3
2 min read

Cushing’s disease, also known as hyperadrenocorticism (HAC), is a condition that affects many middle-aged and senior dogs. If your pup has been drinking more water than usual, panting excessively, or seems to be gaining weight despite eating normally, Cushing’s could be the reason.

Let’s break down what this disease is, how it’s diagnosed, and what treatment and long-term management look like.

What Is Cushing’s Disease?

Cushing’s disease occurs when a dog’s body produces too much cortisol, the stress hormone. Cortisol plays an important role in managing stress and inflammation, but too much of it over time can lead to serious health problems.

There are three main causes:

Pituitary-dependent Cushing’s (PDH): The most common form, caused by a benign tumor on the pituitary gland that triggers excess cortisol production.
Adrenal tumors: Less common, but can be either benign or malignant, occurring on one of the adrenal glands.
Steroid-induced Cushing’s: Caused by long-term use of steroid medications.

What Are the Signs?

Cushing’s often develops gradually, and the symptoms may be mistaken for normal aging. Common signs include:

Excessive thirst and urination
Increased appetite
Pot-bellied appearance
Hair loss or poor coat quality
Panting
Muscle loss or weight gain
Skin thinning or discoloration
Recurring infections (especially skin or urinary tract)

If your dog is showing several of these symptoms, it’s time to talk to your vet.

How Is It Diagnosed?

Diagnosing Cushing’s requires a combination of clinical signs and lab tests. Your vet may recommend one or more of the following:

Low-dose dexamethasone suppression test (LDDS): The most commonly used diagnostic test.
ACTH stimulation test: Often used to monitor treatment, but sometimes used for diagnosis.
Urine cortisol-to-creatinine ratio: A screening tool that must be followed by more specific testing if positive.
Ultrasound or additional hormone tests may be used to determine if the issue is pituitary or adrenal in origin.

Treatment Options

For dogs with an adrenal tumor, surgery may be an option. But for most dogs, especially those with PDH, medication is the mainstay of treatment.

The FDA-approved medication Vetoryl® (trilostane) is the most commonly prescribed drug for managing Cushing’s. It helps reduce cortisol production and control symptoms. Most pet owners notice improvements in thirst, urination, and energy within a few weeks of starting treatment.

Monitoring and Safety

Because Vetoryl affects hormone levels, regular monitoring is essential to ensure your dog is getting the right dose. This involves:

Recheck appointments 10–14 days after starting or adjusting the dose
Routine ACTH stimulation tests every 3 months
Bloodwork (chemistry panel, CBC, and urinalysis) every 6–12 months

While Vetoryl is well tolerated, some dogs may show side effects like lethargy, vomiting, or loss of appetite. If this occurs, stop the medication and contact your vet immediately.

The Bottom Line

Cushing’s disease is a lifelong condition, but with proper diagnosis, treatment, and monitoring, many dogs go on to live healthy, happy lives. Stay alert to the signs, work closely with your vet, and you’ll help your dog feel like themselves again.

Want to learn more or explore treatment options? Don’t hesitate to book a consultation with your veterinary team.