Cushing’s disease, otherwise known as hyperadrenocorticism (big word, I know!) is the overproduction of cortisol, a hormone in the adrenal glands which are located in the belly near the kidneys.
What does cortisol do?
Cortisol is the ‘fight or flight’ hormone that is released by the adrenal glands in small amounts when your dog is stressed. It is a naturally occurring steroid that suppresses the immune system therefore reducing inflammation, pain and swelling.
Dogs need cortisol but too much of it becomes toxic to our dogs. It also affects blood pressure, glucose production, electrolyte balance, immune function and fat metabolism.
Common symptoms of Cushing’s disease are:
Drinking and urinating more frequently
There are two types of Cushing’s disease; Pituitary dependent and Adrenal dependent.
This disease is very rare in cats, and is more commonly seen in dogs over the age of 6.
The most common type of Cushing’s is pituitary dependent. This is caused by the overproduction of a hormone by the pituitary gland in the brain that in turn controls the amount of cortisol produced by the adrenal glands.
The treatment for this type of Cushing’s is lifelong oral medication.
The prognosis for pituitary dependent Cushing’s with treatment is usually good.
Appetite and water consumption usually return back to normal within a few weeks, whereas full return of the fur may take several months.
Adrenal dependent Cushing’s is caused by a tumor on the adrenal gland, causing an overproduction of cortisol. Oral medication may be effective in controlling the symptoms, but more often, it is treated by surgically removing the adrenal gland.
This type of Cushing’s may be cured if the surgery is successful, and the tumour is not malignant.
Adrenal gland tumors can spread to other parts of the body, and if this is the case, the cancer cannot be removed by surgery, and prognosis is less favourable.
There is no single test to diagnose Cushing’s disease. The history, physical exam and initial blood/urine tests will often tell us if Cushing’s disease may be of suspicion. Further blood tests, and sometimes xrays or ultrasound can help in determining whether Cushing’s disease is present, and help us to find out which type we are dealing with.
Cushing’s can be a very confusing disorder for many owners, and sometimes owners may find it difficult to understand.
If you’d like any further information, or suspect that your dog has Cushing’s, give our friendly staff a call, and make an appointment to see one of our vets.