Cushing’s Disease in dogs

isolated dog


  • Cushing’s disease is a condition caused by high levels of steroid in the body, normally produced in precise amounts by the adrenal glands.
  • Cushing’s disease causes a wide range of symptoms, such as excessive drinking and weeing, bald patches and a pot-belly.
  • Treatment for Cushing’s involves daily medication to reduce steroid production.
  • With treatment, the outlook for a dog with Cushing’s is good.
  • Although Cushing’s can affect any dog, it’s more common in middle-aged, small breeds such as terriers, poodles and dachshunds.

What is Cushing’s Disease?

Cushing’s disease (also known as hyperadrenocorticism) is a condition that develops due to high levels of steroid in the body. Steroid is normally produced by the adrenal glands and the amount produced is controlled by signals from the brain. Cushing’s disease develops when the adrenal gland becomes overactive due to:

  1. A tiny brain tumour – that sends too many signals to the adrenal glands, telling them to produce steroid (most common).
  2. An adrenal gland tumour – that causes the adrenal gland to become overactive and produce more steroid than normal.

The most common cause of Cushing’s is a tiny tumour in the brain, this may sound scary but it is usually a very small, benign tumour that causes no problems other than Cushing’s. It is not the same as an aggressive cancerous brain tumour.

High dose steroid medication - occasionally, Cushing’s is brought on by long-term, high dose steroid medication.

illustration showing adrenal gland in dogs

The adrenal glands usually produce steroid. Click image to enlarge.


Common symptoms of Cushing’s include:

Illustration showing Cushing's disease in a dog

Symptoms of Cushing's include a pot belly. Click image to enlarge.

When to contact your vet

Contact your vet if you think your dog has symptoms of Cushing’s, even if they seem otherwise well. It will help your vet if you take a urine sample and a note of how much your dog drinks in a 24-hour period. Watch our videos below for guidance on how to collect a urine sample and measure how much your dog is drinking.

How to collect a urine sample

How to measure how much your dog is drinking


Dogs with Cushing’s disease often develop a unique appearance, so your vet may suspect the condition simply by looking at your dog. However, before treatment can begin, they will need to confirm their suspicions with blood tests, urine tests and possibly a scan.


Medication. Most cases of Cushing’s can be treated with medication to control steroid production. It’s important to give the correct dose because if too much is given, steroid levels may drop dangerously low and cause Addison’s disease (hypoadrenocorticism). Contact your vet immediately if you suspect your dog has had an overdose of their medication.

Surgery. Specialist vets may operate to remove the tumour in the adrenal gland or brain but it’s important to be aware that these surgeries have risks and are expensive.

Ongoing care

Regular vet checks will be necessary to monitor your dog’s progress, blood tests may be necessary to check your dog’s levels from time to time.

Home care

Monitoring. Monitor your dog and keep a note of any new or changing symptoms.

Drinking and peeing. Never restrict your dog’s access to water and make sure they always have somewhere to pee. It can take a few weeks for symptoms to subside and they may always drink and pee a little more than they used to. It will help your vet if you keep a water diary i.e. every 1-2 weeks, make a note of how much your dog drinks in a 24-hour period.


With treatment. If your dog responds well to treatment, their symptoms are likely to start improving within a few weeks and their outlook is very good. Many dogs with well-controlled Cushing’s, live a relatively normal and happy life for many years.

Without treatment. Some dog’s with Cushing’s disease live without treatment for some time, but tend to be happier and healthier with medication.


There isn’t anything you can do to stop your dog developing Cushing’s disease.


Treatment for Cushing’s can become very expensive, especially because it’s an ongoing condition that needs lifelong medication. It’s very important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. There is often more than one treatment option available, so if one doesn’t work for you and your pet, your vet may be able to offer another.

Consider insuring your dog as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.


Will long-term steroid medication give my dog Cushing’s?

High doses of steroids over a long period can cause Cushing’s. Some dogs with chronic conditions such as allergic skin disease, immune mediated disease and Addison’s need long-term steroid medication. Your vet will be aware of the risks of giving long-term steroids and will always try to give the lowest effective dose.

Published: August 2019

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Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst