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Cushing’s Disease (Hyperadrenocorticism) in Dogs: Symptoms, Causes, Treatment, and Prevention

Cushing’s disease, medically known as hyperadrenocorticism, is an endocrine disease in which a dog’s body produces too much cortisol, the hormone that regulates stress response, metabolism, and immune function.

Chronic excess cortisol gradually affects nearly every body system, which is why Cushing’s disease produces so many different symptoms, but the condition is manageable long-term with the right diagnosis and treatment plan. This guide covers what causes Cushing’s disease, its symptoms, how it’s diagnosed, how it’s treated, whether it can be prevented, and when to see a veterinarian.

This guide covers what Cushing’s disease is, what causes it in dogs, its symptoms, how it’s diagnosed, how it’s treated, whether it can be prevented, when to see a vet, and what else people ask.

What Is Cushing’s Disease in Dogs?

Cushing’s disease, or hyperadrenocorticism, is a chronic endocrine disease caused by sustained overproduction of cortisol, a hormone the adrenal glands release in response to the body’s signals. Cortisol plays a genuine role in regulating metabolism, blood pressure, and immune response in normal amounts, but chronically elevated levels gradually damage tissue, suppress the immune system, and disrupt normal metabolic function throughout the body. The disease typically develops gradually in middle-aged to older dogs, which is part of why its early signs are often mistaken for normal aging.

What Causes Cushing’s Disease in Dogs?

Most cases of Cushing’s disease in dogs stem from a tumor on the pituitary gland, a small gland at the base of the brain that signals the adrenal glands to produce cortisol; this tumor causes the pituitary to send an excessive signal, driving the adrenal glands to overproduce the hormone. A smaller share of cases comes from a tumor directly on one of the adrenal glands themselves, which produces excess cortisol independent of the pituitary’s signal. A third form, called iatrogenic Cushing’s disease, results from long-term use of steroid medications rather than a tumor, and it can develop in any dog on extended steroid treatment for an unrelated condition.

What Are the Symptoms of Cushing’s Disease in Dogs?

The most common early symptoms of Cushing’s disease are increased thirst, increased urination, and an increased appetite, all driven by cortisol’s effect on the body’s fluid balance and metabolism. Many affected dogs develop a pot-bellied appearance as cortisol weakens abdominal muscles and redistributes fat, along with thinning hair, fragile skin, and a dull, patchy coat. Excessive panting, lethargy, muscle weakness, and a higher rate of skin infections also commonly appear as the disease progresses, since chronic excess cortisol suppresses normal immune function.

How Is Cushing’s Disease in Dogs Diagnosed?

Diagnosing Cushing’s disease typically starts with an ACTH stimulation test or a low-dose dexamethasone suppression test, both of which measure how a dog’s adrenal glands respond to specific hormonal triggers. A urine cortisol-to-creatinine ratio test can help rule the disease out when results are negative, though it’s less specific for confirming a positive diagnosis on its own. Once Cushing’s disease is confirmed, imaging such as ultrasound or CT scanning helps a veterinarian determine whether the cause is a pituitary or adrenal tumor, since that distinction shapes the treatment plan.

How Is Cushing’s Disease in Dogs Treated?

Most dogs with pituitary-related Cushing’s disease are treated with daily oral medication, most commonly trilostane, which reduces cortisol production and requires regular veterinary monitoring and bloodwork to keep the dose properly calibrated. Adrenal tumors are sometimes surgically removed when the tumor is operable and the dog is a good surgical candidate, which can resolve the disease entirely in successful cases. Iatrogenic Cushing’s disease caused by steroid medication is treated by gradually tapering the steroid dose under veterinary supervision, since stopping it abruptly can be dangerous.

Can Cushing’s Disease in Dogs Be Prevented?

Spontaneous Cushing’s disease caused by a pituitary or adrenal tumor generally can’t be prevented, since tumor development isn’t something an owner can control. Iatrogenic Cushing’s disease is the exception, and it can often be avoided by using the lowest effective steroid dose for the shortest necessary duration whenever a veterinarian prescribes long-term steroid treatment for another condition. Regular veterinary checkups that catch early symptoms give a dog the best chance at early diagnosis and treatment even when the disease itself isn’t preventable.

When Should You See a Vet for Cushing’s Disease in Dogs?

See a veterinarian if a dog shows a combination of increased thirst, increased urination, a pot-bellied appearance, or noticeable hair thinning, since these are the classic signs that prompt a Cushing’s disease workup. Recurrent skin infections or wounds that heal slowly are also worth mentioning to a veterinarian, since chronic excess cortisol’s immune-suppressing effects can show up this way before the more obvious symptoms appear. A dog already diagnosed with Cushing’s disease should see a veterinarian promptly for any new or worsening symptoms, since the medication dose may need adjustment.

What Else Do People Ask About Cushing’s Disease in Dogs?

The questions below cover whether Cushing’s disease is curable, which dogs are most at risk, how long dogs live with the condition, and whether Cushing’s disease is painful.

Is Cushing’s disease in dogs curable?

Cushing’s disease caused by an operable adrenal tumor can sometimes be cured through surgical removal, but most cases, which stem from a pituitary tumor, are managed rather than cured with lifelong medication. Iatrogenic Cushing’s disease caused by steroid medication typically resolves once the steroid is properly tapered off under veterinary guidance.

Which dogs are most at risk for Cushing’s disease?

Middle-aged to older dogs face the highest risk for Cushing’s disease, and certain breeds, including Poodles, Dachshunds, Boston Terriers, and Boxers, show a documented elevated predisposition. Dogs on long-term steroid medication for an unrelated condition also face an elevated risk of the iatrogenic form.

How long do dogs live with Cushing’s disease?

Many dogs with well-managed Cushing’s disease live comfortably for years after diagnosis, since the medication used to control cortisol production is generally effective at managing symptoms long-term. Untreated Cushing’s disease, by contrast, tends to shorten lifespan and quality of life as the complications of chronic excess cortisol accumulate over time.

Is Cushing’s disease painful for dogs?

Cushing’s disease itself isn’t typically described as painful, though the secondary effects, including muscle weakness, skin infections, and in some cases bladder stones or diabetes, can cause real discomfort if the disease goes untreated. Proper treatment significantly improves a dog’s day-to-day comfort and quality of life.

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