Cushing’s Disease in Dogs: Signs, Causes & Treatment
Cushing’s disease (hyperadrenocorticism) is one of the most common hormonal disorders in middle-aged and senior dogs, caused by chronic overproduction of cortisol. This guide covers the causes, signs, diagnosis, and treatment options every dog owner should know.
This guide is for informational purposes and is not a substitute for veterinary diagnosis or treatment. Always consult a veterinarian if you suspect your dog has Cushing’s disease.
What Is Cushing’s Disease?
Cushing’s disease, medically known as hyperadrenocorticism, is a hormonal disorder in which the body produces excessive amounts of cortisol, the primary stress hormone. It is one of the most common endocrine disorders in middle-aged and senior dogs. Cortisol plays an important role in regulating metabolism, immune response, and the body’s stress response in healthy amounts, but chronically elevated levels damage multiple organ systems over time.
There are two main forms of the disease: pituitary-dependent Cushing’s, which accounts for roughly 80–85% of cases and is caused by a small, usually benign tumor on the pituitary gland that overstimulates the adrenal glands, and adrenal-dependent Cushing’s, caused by a tumor directly on one of the adrenal glands. A third, less common form — iatrogenic Cushing’s — results from long-term use of corticosteroid medications rather than a tumor.
Certain breeds, including Poodles, Dachshunds, Boxers, Boston Terriers, and Beagles, appear to be predisposed to the pituitary-dependent form, though any breed can be affected, typically after the age of 6.
Causes & Risk Factors
The underlying cause of Cushing’s disease is almost always a benign tumor — either on the pituitary gland (which sits at the base of the brain and signals the adrenal glands to produce cortisol) or on one of the adrenal glands themselves (located near the kidneys). These tumors disrupt the normal feedback loop that keeps cortisol production in balance, leading to chronic overproduction.
Age is the single biggest risk factor, with most cases diagnosed in dogs over 6 years old, and risk increasing further with age. Certain breeds show a higher predisposition, suggesting a genetic component, though the exact cause of the initial tumor formation is not fully understood.
Iatrogenic Cushing’s, the medication-induced form, occurs when a dog receives corticosteroids (such as prednisone) at high doses or for extended periods, which is why long-term steroid use is always monitored closely by veterinarians and tapered gradually rather than stopped abruptly.
Signs & Symptoms
Cushing’s disease develops gradually, and early signs are often mistaken for normal aging. The most common and recognizable symptoms include increased thirst and urination, increased appetite, and a pot-bellied abdominal appearance caused by weakened abdominal muscles and fat redistribution. Many affected dogs also develop thinning skin, hair loss (particularly along the trunk), and a dull, brittle coat.
Other signs include panting more than usual, lethargy or reduced stamina during exercise, recurrent skin infections, and calcium deposits in the skin (calcinosis cutis) in more advanced cases. Because these symptoms overlap with normal aging and several other conditions, a proper veterinary workup is essential for an accurate diagnosis rather than assuming symptoms are “just old age.”
Left untreated, Cushing’s disease can contribute to more serious complications over time, including diabetes, high blood pressure, blood clots, and increased susceptibility to infections due to a suppressed immune response.
Diagnosis & Treatment Options
Diagnosing Cushing’s disease typically involves a combination of blood work, urinalysis, and specialized hormone tests such as the low-dose dexamethasone suppression test or ACTH stimulation test, which measure how the body’s cortisol levels respond to specific triggers. Abdominal ultrasound is often used afterward to determine whether the cause is pituitary or adrenal in origin, since this affects treatment choice.
Pituitary-dependent Cushing’s is most commonly managed with daily oral medication (such as trilostane or mitotane) that reduces cortisol production, along with regular monitoring blood tests to fine-tune the dose. Adrenal tumors may be surgically removed if operable and caught early, which can potentially cure the disease, though surgery carries more risk and is not appropriate for every dog.
Treatment is typically lifelong for the pituitary form, with periodic ACTH stimulation tests used to adjust medication dosage as the disease and the dog’s needs evolve over time.
What Owners Should Do
If you notice increased thirst, urination, appetite, or a change in your dog’s coat or body shape, schedule a veterinary appointment rather than waiting to see if symptoms resolve on their own — early diagnosis leads to better long-term management. Keep a log of water intake, urination frequency, and appetite changes to share with your veterinarian, since these details help guide the diagnostic workup.
Once diagnosed, consistent medication administration and regular follow-up blood testing are essential — skipping doses or missed monitoring appointments can lead to dangerous under- or over-treatment. Most dogs with well-managed Cushing’s disease can maintain a good quality of life for years after diagnosis.
Because Cushing’s dogs are more prone to infections and slower wound healing, owners should also monitor for skin issues, urinary tract infections, and other secondary problems, and keep up with routine veterinary care rather than treating Cushing’s in isolation.
Frequently Asked Questions
What is the life expectancy of a dog with Cushing’s disease?
Is Cushing’s disease in dogs painful?
Can Cushing’s disease in dogs be cured?
What dog breeds are most at risk for Cushing’s disease?
How is Cushing’s disease diagnosed in dogs?
Noticing increased thirst, urination, or appetite changes in your dog? Schedule a checkup with a local veterinarian through HeiBob’s veterinary directory for proper diagnosis and treatment.