Cushing’s Syndrome

Cushing’s Syndrome


What is Cushing’s Syndrome?

Cushings occurs in animals that have an excessive amount of cortisol, an important chemical that helps to regulate the body’s metabolism.

Cortisol plays a vital role in protein, carbohydrate and fat metabolism and is released into the bloodstream at times of stress to prepare the body for a light or fight response. It is produced by the adrenal glands – two small glands located in the abdomen, next to each kidney. A hormone called ACTH controls the production and release of cortisol from the adrenal glands. ACTH itself is produced by the pituitary gland, a pea-sized gland located at the base of the brain.

The concentration of cortisol in the blood of healthy animals varies greatly throughout the day as the body’s demand fluctuates. For example, during a period of anxiety or illness, it is normal for the levels to up, once this period of stress has passed, the cortisol concentration returns back to normal.

In dogs with Adrenal or Pituitary based Cushings Syndrome, there is an overproduction of cortisol over weeks and months if not longer. Although the concentration of cortisol in the blood of a dog with Cushings also fluctuates greatly, it tends to be, on average, much higher than in healthier dogs. The excessive amount of cortisol released into the bloodstream has a harmful effect on the function of many organs and the body’s metabolism.

The excessive cortisol may also be associated by taking certain cortisol or steroid based medications over a long period, so it is important to use these as instructed, and to alert us to any changes you may note in an individual. This is known as Iatrogenic Cushings Syndrome


What are the signs of Cushing’s Syndrome?

Pituitary or Adrenal based Cushings is usually seen in older dogs. Additionally, small breed dogs are more likely to develop the disease. The most common signs are very similar to those we associate with the normal ageing. This can sometimes make it difficult to spot and later monitor. It is always a good idea whenever possible to keep a note of the changes you see in your dog’s habits, behaviour and appearance.

Iatrogenic Cushings can be seen at any age, but they need to be on a steroid or cortisol based medication (usually tablets, but occasional ointments, creams, eye/ear drops).

So remember to look out for:

  • Drinking more
  • Urinating more, or not managing to get through the night without an accident.
  • Eating more or stealing food
  • Pot bellied appearance and possibly thinner over their backbone
  • Thin skin
  • Thinning of the hair, or a change in its colour or texture.
  • Recurrent skin problems, blackheads or sores
  • Muscle wastage
  • Lethargy, tiredness
  • Excessive panting


They do not need all the signs. In fact, they may only show one or two in a subtle way.



Your veterinary surgeon will initially suspect Cushings Syndrome based on the clinical signs and/or changes in your dog’s appearance such as a “pot belly” or coat changes.  In most cases, the changes in appearance and behaviour occur very gradually, making them easy to overlook. Cushings may also come in tandem with other problems such as diabetes mellitus (sugar diabetes) +/or an underactive thyroid (hypothyroidism).

Links to Diabetes and Hypothyroidism needed

If we suspect Cushings Syndrome will need to perform blood tests to confirm the diagnosis. This often involves a general health profile, followed by a more specific test or tests for the disease, as follows;

ACTH Stimulation Test:

This is the one we most commonly use.

Your pet will need to be pre-starved, i.e. no food for 12 hours beforehand, but they MUST have access to water.

An initial blood sample is taken, followed by an injection of an agent that stimulates the adrenal glands. A second blood sample is then taken 1-2 hours later. After this second sample, your pet can go home and have a meal.

Dexamethasone Suppression Test:

We use this less frequently or sometimes as a backup test to the ACTH Stimulation Test if more clarification is needed.

Again your pet needs to be pre-starved for 12 hours beforehand, still allow water. This consists of 3 blood samples over approximately 8 hours, and an agent that suppresses the adrenal gland.

The Cushings tests are started in a morning, and usually your pet will be admitted for this. Sometimes  an individual pet can go home between blood samples when doing the ACTH Stimulation test, but remember NOT to allow any access to food until their final blood sample is taken (remember, they must have access to water).



Adrenal or Pituitary based Cushings Syndrome cannot be cured. But it can often be managed through tablets, maintaining quality of life for your dog  in a significant number of cases. Your dog will need to be carefully monitored and return for follow-up appointments on a regular basis. Once your vet is happy that your dog is stable, you will normally then need to visit the surgery every 3-6 months* to make sure nothing is affecting your dog’s condition and to repeat monitoring tests.

For those with Iatrogenic Cushings, can we expect a cure. We will devise a staged withdrawal of the relevant medication that is causing this particular problem, tailoring the plan to your pet’s response and needs.


It is important to handle the medication with care, so there is NO risk of you taking any or coming into contact with it. You should always wear gloves, and it should not be handled if you are or could be pregnant. You can purchase your gloves from dispensary if needed.

If your animal is unwell or ‘not right’ for any reason, especially when they are starting the treatment, it is essential that you talk to a Veterinary Surgeon for advice. When you call, ask the nurse or receptionist for the vet to assess the situation as vague signs that can often not be significant in other diseases, can be very important with dogs on Cushings medication.

For repeat medications, please telephone your nearest surgery in advance or submit a request through our online pharmacy. Please give at least 2 weekday’s notice.

For more information go to