Cushing’s disease in dogs
- Cushing’s disease – or hyperadenocorticism – is a condition where the dog’s body produces too much of the hormone ‘cortisol’
- Signs your dog may have Cushing’s include drinking lots and urinating frequently, hair loss, weight gain, panting, changes to the skin’s appearance and abdominal swelling – but these can be signs of lots of other health conditions too and many healthy older dogs get a bit of a middle aged spread anyway
- Cushing’s is fairly common in middle aged and older dogs. Affected dogs will likely need to take medication to manage the illness for life.
What is Cushing’s disease?
Cushing's disease, or hyperadrenocorticism to give it its proper name, is a condition where the body overproduces the cortisol steroid hormone. It's a fairly common condition in middle aged and older dogs.
Dogs normally need some steroids for their bodies to function properly and they are produced by the adrenal gland, which sits next to the kidney. The adrenal gland is sent messages to produce cortisol by the pituitary gland, which sits at the base of the brain. If a dog gets a growth on either of these glands, this can send hormone production into overdrive which leads to a number of symptoms.
The majority of Cushing’s cases are caused by a benign tumour on the pituitary gland. Tumours on the adrenal gland also cause this disease, but are less common. High level use of steroids, used to treat immune disorders or allergies, can also cause Cushing’s disease.
Symptoms of Cushing’s disease in dogs
Most owners will notice excess thirst and urination. One of the first signs owners often notice is that their dog suddenly begins needing to go out to the toilet in the middle of the night.
There can also be hair loss, weight gain, panting, skin changes, lowered immunity and abdominal swelling, which can make the belly appear to sag. A lack of energy is another symptom you may notice.
In most cases the symptoms are quite mild and for this reason– along with the fact that there could be other causes of these signs – getting a confirmed diagnosis can be challenging.
How does Cushing’s disease affect dogs?
When a dog becomes stressed, their body releases the cortisol hormone. Cortisol effectively tells the body it is about to have to work quickly to fight off the cause of the stress – think of a ‘fight or flight’ situation where a quick reaction is needed. A dog’s body reacts to this by speeding up the metabolism and releasing energy in the form of fat and sugar, and holding on to water. This is a perfectly natural response to a stressor in a healthy dog during stressful moments.
Each time cortisol is produced, a dog’s body will react by releasing enough energy to overcome the stressor. In a dog with Cushing’s disease, too much cortisol is being produced. In the long term this can cause changes which can make the dog prone to health problems, such as skin changes and infections, or they may become more prone to diabetes.
How do you test for and diagnose Cushing’s?
There isn’t just one simple test that can diagnose Cushing’s, and the symptoms of Cushing’s are very similar to many other conditions that affect dogs in the same age groups, so it can take a bit of time to diagnose. And dogs with other longstanding health problems are more likely to test positive, even if they don’t actually have Cushing’s disease.
Your vet will want to know lots about your dog’s health history and any symptoms they’ve been experiencing. They will then give your dog a physical full body check. Your vet will need to take a blood sample and urine sample. Some further tests may be required.
Treating and managing Cushing’s in dogs
It’s not always necessary to treat Cushing’s disease – treatment is not without risks, and you should discuss with your vet whether treatment is right for you and your dog.
Treatment for Cushing’s disease depends on the type your dog has but medical therapy (tablets) can be used in most cases, as surgery is usually a specialist option.
If your dog’s illness is due to the most common cause, a benign pituitary tumour, they may be prescribed daily tablets to help manage the disease. Treatment with medicine may not be necessary for dogs with mild symptoms; your vet may want to closely monitor your pet for a while first. Specialist surgery to remove pituitary tumours is also available.
Dogs whose Cushing’s disease is caused by a growth on the adrenal gland will need a scan to see whether their condition is benign or malignant. If there is just one tumour, your vet may advise a course of medication to shrink it and possibly surgery to remove it. In some cases, further tumours may spread through the body and in severe cases are unfortunately untreatable.
Dogs who have developed Cushing’s due to taking steroids for other health conditions such as allergies or immunity issues will needs to be weaned off those steroids under the advice of a vet. Coming off steroids too quickly can lead to further, potentially-fatal, problems.
While Cushing’s disease cannot be cured, it can be managed in most cases but it is a costly condition to treat.
Owners with dogs who are being treated for Cushing’s with tablets will need to give them to their pet for the rest of their pet’s life. You will need to visit your vet regularly with your dog as treatment can be dangerous without careful monitoring, which often includes regular blood tests.