Cushing's Disease in Dogs: Signs, Tests and Treatment

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

A dog with a pot belly, thinning coat and constant thirst may have Cushing's disease.

What it is

Cortisol is a hormone made by the adrenal glands that helps manage stress, metabolism and immunity. In Cushing's disease, the body produces too much. Most cases are caused by a small tumor in the pituitary gland, which stimulates the adrenal glands, while others involve a tumor in an adrenal gland. Long-term steroid medication can cause similar effects, which is called iatrogenic Cushing's.

Signs

• Increased thirst and urination. See excessive thirst and urination in dogs
• Increased appetite
• Pot-bellied appearance
• Panting
• Thin skin, hair loss and slow regrowth. See dog hair loss causes
• Recurring skin infections. See pyoderma in dogs
• Muscle weakness and lethargy
• Bladder infections

These develop slowly and are often dismissed as aging.

Complications

Cushing's can raise the risk of diabetes, pancreatitis, high blood pressure, blood clots, bladder stones and infections. See diabetes in dogs and pancreatitis in dogs.

Diagnosis

Cushing's can be tricky to diagnose. Vets assess signs, bloodwork and urinalysis, and then use specific tests such as the ACTH stimulation test, low-dose dexamethasone suppression test or urine cortisol-to-creatinine ratio. Imaging, such as abdominal ultrasound, helps tell pituitary from adrenal disease.

Treatment

• Medication: trilostane is commonly used, and mitotane in some cases, under strict veterinary supervision with regular testing
• Surgery: removal of an adrenal tumor in selected dogs
• Radiation for pituitary tumors in some cases
• Managing complications, including infections and diabetes

Medication must be monitored closely, as dosing changes may be needed and too much can cause side effects. Never adjust doses yourself.

When treatment may not be needed

Some dogs with mild signs or very advanced age may not need treatment. Your vet will discuss risks and benefits.

Monitoring

Expect regular rechecks with bloodwork and ACTH stimulation tests. Keep a diary of thirst, appetite, energy, panting and coat, and report vomiting, lethargy or collapse promptly, since they may signal overdose or other problems.

Home care

1. Give medication with food as directed.
2. Keep water available.
3. Maintain lean weight.
4. Provide regular, moderate exercise.
5. Care for the skin and treat infections promptly.

Costs and planning

Long-term testing and medication are an ongoing expense. Ask your vet to outline costs and consider insurance early.

Common mistakes

• Assuming it is normal aging
• Changing the dose without advice
• Skipping monitoring tests
• Ignoring weakness or vomiting while on medication

Troubleshooting

• My dog is more lethargic on medication: call your vet right away.
• Panting continues: ask about recheck testing and pain.
• Thirst has returned: book a recheck.

A simple plan

1. Recognize the signs.
2. Pursue testing.
3. Start and monitor treatment.
4. Recheck regularly.

Real-life examples

A poodle's thirst and pot belly improve after starting trilostane. A terrier's adrenal tumor is removed surgically. A dachshund with mild signs is monitored without medication. Plans vary.

Staying consistent

Regular monitoring helps keep dogs comfortable on treatment.

Questions to ask your vet

Ask whether your dog's signs justify treatment, which test confirmed the diagnosis, whether the tumor is pituitary or adrenal, what side effects to watch for and how often rechecks are needed. Ask what signs of overdose look like and what you should do if your dog stops eating on medication.

Skin and coat care

Cushing's can make skin thin and fragile and prone to infection. Bathe gently with vet-approved shampoos, check for pimples or crusts and treat infections promptly. Calcinosis cutis, hard mineral deposits in the skin, also occurs in some dogs and needs veterinary attention. See how to bathe a dog at home.

The takeaway

Cushing's disease is common in older dogs. Testing is detailed and treatment needs careful monitoring.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.