Dog Cushing’s Disease: Symptoms, Diagnosis & Treatment

Last updated: May 6, 2026

If your older dog has been drinking water like they cannot get enough, gaining weight around the middle, and losing fur in patches, you may be dealing with something more than normal aging. Dog Cushing’s disease — also called hyperadrenocorticism — is one of the most common hormonal disorders in middle-aged and senior dogs, and its symptoms often creep in so gradually that owners mistake them for the natural slowing down that comes with age. Understanding this condition early can make a meaningful difference in your dog’s comfort and quality of life.

What Is Cushing’s Disease in Dogs?

Cushing’s disease occurs when a dog’s body produces too much cortisol, a hormone made by the adrenal glands. Cortisol plays important roles in regulating metabolism, managing stress, controlling blood sugar, and reducing inflammation. In normal amounts, it is essential. In excess, it causes widespread damage to nearly every system in the body.

The condition is named after Harvey Cushing, the neurosurgeon who first described the syndrome in humans in the early twentieth century. In dogs, it most commonly appears after the age of six, with the average diagnosis occurring around ten years old. It develops slowly, which is part of what makes it tricky to catch — many owners live with the symptoms for months before seeking veterinary attention, assuming their dog is simply getting older.

Because dog Cushing’s disease affects so many body systems at once, the list of potential symptoms is long and varied. That same breadth, however, means there are usually multiple signs pointing in the same direction once you know what to look for.

Types of Cushing’s Disease: Pituitary vs. Adrenal

There are two primary forms of Cushing’s disease in dogs, and the distinction matters because it affects both treatment and prognosis.

Pituitary-dependent Cushing’s disease accounts for roughly 80 to 85 percent of all cases. It occurs when a small tumor on the pituitary gland — a pea-sized structure at the base of the brain — produces too much adrenocorticotropic hormone (ACTH). ACTH is the chemical messenger that tells the adrenal glands to release cortisol. When the pituitary sends too much of that signal, the adrenal glands respond by overproducing cortisol even though the body does not need it. Most pituitary tumors in dogs are benign and small, though a small percentage are larger and can cause neurological symptoms as they grow.

Adrenal-dependent Cushing’s disease accounts for the remaining 15 to 20 percent of cases. Here, a tumor grows directly on one of the adrenal glands and produces cortisol independently, ignoring the normal feedback signals from the brain. Adrenal tumors can be either benign (adenomas) or malignant (carcinomas). The distinction between these two matters significantly when considering surgical options.

A third, less common form — iatrogenic Cushing’s disease — is caused by the long-term use of corticosteroid medications such as prednisone. When a dog receives steroids for an extended period to manage allergies, autoimmune disorders, or other inflammatory conditions, the external cortisol can produce the same symptoms as the disease itself. This form typically resolves when the medication is gradually tapered under veterinary supervision.

Symptoms of Cushing’s Disease in Dogs

The symptoms of dog Cushing’s disease tend to develop slowly and overlap with other conditions, which is why the disease is sometimes called “the great pretender.” No single symptom confirms the diagnosis on its own, but the combination of several together is what raises suspicion.

Excessive thirst and urination. This is often the first symptom owners notice. Dogs with Cushing’s disease may drink two to three times their normal amount of water and need to urinate far more frequently, including having accidents in the house — something that can be especially distressing for a dog that has been reliably house-trained for years.

Increased hunger. Elevated cortisol stimulates appetite significantly. Dogs with Cushing’s often become unusually food-driven, begging constantly, scavenging, or eating things they would normally ignore. Some owners describe it as an almost desperate hunger.

Pot-bellied appearance. Cortisol causes fat to redistribute toward the abdomen and weakens the abdominal muscles. The result is a round, sagging belly that is one of the most visually recognizable signs of the disease. This change is often mistaken for simple weight gain or bloating.

Hair loss and skin changes. Thinning fur, particularly on the flanks, tail, and back — usually symmetrical on both sides — is a hallmark symptom. The skin underneath may become thin, darkly pigmented, or prone to bruising. Some dogs develop recurrent skin infections or slow-healing wounds. The coat may lose its luster and feel dry or brittle.

Excessive panting. Dogs with Cushing’s disease often pant heavily, even at rest and in cool environments. This happens because cortisol redistributes fat to the chest and abdomen, putting pressure on the diaphragm, and because the hormone affects respiratory drive.

Lethargy and muscle weakness. Although the increased appetite might suggest energy, many dogs with Cushing’s become less active. Cortisol breaks down muscle tissue over time, leading to weakness, difficulty climbing stairs, and a general reluctance to exercise. Some dogs develop a stiff or awkward gait.

Recurrent infections. Because excess cortisol suppresses the immune system, dogs with Cushing’s disease are more vulnerable to urinary tract infections, skin infections, and ear infections. If your dog seems to cycle through infections repeatedly despite treatment, Cushing’s should be on the list of things to investigate.

Diagnosing Cushing’s Disease in Dogs

Diagnosing dog Cushing’s disease is not straightforward. There is no single definitive test, and veterinarians typically use a combination of blood work, urine analysis, and specialized hormone tests to build the picture.

Routine blood work and urinalysis. Initial screening often reveals elevated liver enzymes — particularly alkaline phosphatase (ALP) — dilute urine, elevated cholesterol, and sometimes elevated blood sugar. These findings alone do not confirm Cushing’s, but they raise the index of suspicion, especially when combined with the clinical symptoms described above.

Low-dose dexamethasone suppression test (LDDS). This is the most commonly used screening test. The dog receives a small injection of dexamethasone, a synthetic steroid, and blood cortisol levels are measured at four and eight hours afterward. In a healthy dog, the dexamethasone suppresses cortisol production. In a dog with Cushing’s, cortisol levels remain elevated because the feedback loop is not working properly. The LDDS test is sensitive — it catches most cases — but it can occasionally produce false positives in stressed or ill dogs.

ACTH stimulation test. This test measures how the adrenal glands respond to a synthetic version of ACTH. Blood cortisol is measured before and one to two hours after the injection. An exaggerated cortisol response suggests Cushing’s disease. This test is also used to monitor treatment effectiveness once medication has started. It is slightly less sensitive than the LDDS test for initial diagnosis but is the preferred method for detecting iatrogenic Cushing’s.

High-dose dexamethasone suppression test. Once Cushing’s disease is confirmed, this test can sometimes help distinguish between pituitary and adrenal forms. Pituitary tumors will often show some suppression at higher dexamethasone doses, while adrenal tumors typically will not.

Abdominal ultrasound. Imaging is important for identifying adrenal tumors, assessing adrenal gland size, and checking for other complications. In pituitary-dependent cases, both adrenal glands are usually enlarged. In adrenal-dependent cases, one gland is typically enlarged while the other may be smaller than normal. An MRI or CT scan may be recommended if a large pituitary tumor is suspected.

Treatment Options for Cushing’s Disease

Treatment depends on the type of Cushing’s disease, the dog’s overall health, the severity of symptoms, and the owner’s ability to commit to ongoing monitoring. There is no outright cure for most cases, but effective management can significantly improve quality of life.

Trilostane (Vetoryl). Trilostane is the most commonly prescribed medication for dog Cushing’s disease in many countries. It works by inhibiting an enzyme involved in cortisol production, effectively reducing the amount of cortisol the adrenal glands release. It is given orally, usually once or twice daily with food. Dogs on trilostane require regular ACTH stimulation tests — typically at two weeks, one month, three months, and then every three to six months — to ensure the dose is correct and cortisol levels are not dropping too low. Over-suppression of cortisol can cause an Addisonian crisis, which is a medical emergency.

Mitotane (Lysodren). Mitotane is an older medication that works differently — it selectively destroys the cortisol-producing layers of the adrenal glands. It is effective but carries more risk of serious side effects than trilostane, which is why it has fallen out of favor as a first-line treatment in many practices. It requires careful induction dosing and close monitoring. Mitotane may still be recommended in cases where trilostane is not effective or not tolerated.

Surgery. For adrenal-dependent Cushing’s caused by a benign tumor, surgical removal of the affected adrenal gland (adrenalectomy) can be curative. This is a major surgery with significant risks, including hemorrhage, and it should be performed by an experienced veterinary surgeon. For pituitary tumors, surgical removal is less commonly attempted in dogs than in humans, though radiation therapy may be an option for large or growing pituitary tumors that cause neurological symptoms.

Discontinuing steroids. For iatrogenic Cushing’s, the treatment is gradually tapering the corticosteroid medication under veterinary guidance. This must be done slowly — abruptly stopping steroids can cause a dangerous cortisol deficiency. The underlying condition that required steroids in the first place will also need an alternative management plan.

Managing Cushing’s Disease at Home

Living with a dog with Cushing’s disease requires patience, consistency, and close communication with your veterinarian. Here are practical steps that make a real difference in day-to-day life.

Keep water accessible at all times. Dogs with Cushing’s are genuinely thirsty — restricting water to reduce accidents is not appropriate and can lead to dehydration. Instead, provide multiple water bowls, take your dog out more frequently, and consider using waterproof pads or dog diapers if house-training accidents become an issue.

Monitor appetite and weight. Feed a consistent, balanced diet and resist the urge to give in to every plea for food. Excess weight puts additional strain on already-weakened muscles and joints. Your veterinarian may recommend a diet that is moderate in fat and higher in fiber to help manage hunger.

Protect the skin. Thin, fragile skin is vulnerable to tears, bruising, and infection. Avoid rough play, keep nails trimmed to prevent scratching injuries, and address any skin infections promptly. Regular baths with a gentle, veterinary-recommended shampoo can help with skin health.

Maintain gentle exercise. While dogs with Cushing’s may tire more easily, regular low-impact activity helps maintain muscle mass and supports mental health. Short, frequent walks are better than long, strenuous outings. Let your dog set the pace.

Stay on top of veterinary appointments. Treatment monitoring is not optional. Regular blood tests ensure medication dosages remain appropriate and catch complications early. Keep a log of your dog’s water intake, appetite, energy level, and any symptoms to share with your vet at each visit.

If you are considering adopting a dog and the dog has been diagnosed with Cushing’s, know that many dogs live comfortably with the condition for years with proper management. It requires commitment, but it is very much a manageable disease.

Prognosis: What to Expect

The prognosis for dog Cushing’s disease depends on the type, the dog’s age and overall health, and how well the condition responds to treatment. With appropriate medical management, many dogs with pituitary-dependent Cushing’s live two to three years or longer after diagnosis, often with a good quality of life. Some dogs do considerably better than that.

Adrenal-dependent Cushing’s has a more variable prognosis. If the adrenal tumor is benign and can be surgically removed, the outcome can be excellent — effectively a cure. Malignant adrenal tumors that have spread carry a less favorable outlook, though medical management can still provide meaningful time with a reasonable quality of life.

The most important factor in prognosis is consistent treatment and monitoring. Dogs whose cortisol levels are well-controlled tend to see their symptoms improve significantly — drinking normalizes, energy returns, skin and coat begin to recover, and the pot-bellied appearance gradually reduces. Left untreated, Cushing’s disease increases the risk of serious complications including diabetes, blood clots, kidney disease, and systemic infections.

Dog Breeds at Higher Risk for Cushing’s Disease

While Cushing’s disease can occur in any breed, certain breeds appear to be predisposed. Breeds that show up more frequently in veterinary literature on the condition include:

• Poodles (all sizes, but especially Miniature Poodles)
• Dachshunds
• Boston Terriers
• Boxers
• Beagles
• German Shepherds
• Golden Retrievers
• Labrador Retrievers
• Yorkshire Terriers
• Dandie Dinmont Terriers
• Staffordshire Bull Terriers

If you own one of these breeds and your dog is middle-aged or older, it is worth mentioning Cushing’s to your veterinarian during routine wellness visits — especially if you have noticed any of the symptoms described above. You can learn more about breed-specific health considerations in our dog breeds directory.

Frequently Asked Questions

Is Cushing’s disease in dogs fatal?

Cushing’s disease itself is not immediately fatal, but left untreated it significantly increases the risk of life-threatening complications such as blood clots (pulmonary thromboembolism), uncontrolled diabetes, severe infections, and kidney failure. With appropriate treatment and monitoring, most dogs with Cushing’s can live comfortably for a meaningful period after diagnosis.

How much does it cost to treat Cushing’s disease in dogs?

Costs vary depending on the treatment approach and your location. Trilostane medication typically costs between 50 and 200 dollars per month depending on the dog’s size and dosage. Regular monitoring blood tests add several hundred dollars per year. Surgery for adrenal tumors, when appropriate, can cost several thousand dollars. While the expenses are real, many owners find the investment worthwhile given the improvement in their dog’s quality of life.

Can Cushing’s disease in dogs be cured?

Adrenal-dependent Cushing’s caused by a benign tumor can sometimes be cured through surgical removal of the affected adrenal gland. Iatrogenic Cushing’s resolves when the offending steroid medication is properly tapered. Pituitary-dependent Cushing’s — the most common form — is managed rather than cured, but effective management can control symptoms and allow a good quality of life for years.

What happens if Cushing’s disease goes untreated?

Without treatment, cortisol levels continue to rise, and the symptoms progressively worsen. The immune system becomes increasingly suppressed, making the dog vulnerable to serious infections. The risk of developing diabetes, high blood pressure, blood clots, and protein-losing kidney disease all increase. The dog’s muscles continue to weaken, skin becomes more fragile, and overall quality of life declines steadily.

How is Cushing’s disease different from Addison’s disease in dogs?

They are essentially opposite conditions. Cushing’s disease involves too much cortisol, while Addison’s disease (hypoadrenocorticism) involves too little. Addison’s disease can also occur as a complication of Cushing’s treatment if medication suppresses cortisol production too aggressively, which is why regular monitoring during treatment is so important.

Should I adopt a dog with Cushing’s disease?

Dogs with Cushing’s disease can make wonderful companions and many live happily for years with treatment. If you are prepared for the commitment of regular veterinary visits, daily medication, and monitoring, adopting a dog with a managed chronic condition can be deeply rewarding. These dogs are often overlooked in shelters, and they deserve comfortable homes just as much as any other dog.