Small Talk - Autumn 2018

How is cortisol produced? Two small glands situated near the kidneys - the adrenal glands - produce cortisol. The production and release of cortisol from the adrenal glands is controlled by the hormone ACTH. A pea-sized gland at the base of the brain called the pituitary gland is responsible for the production of ACTH. Cushing’s disease Pituitary-dependent Cushing’s disease This is the most common form of the disease. It occurs as a result of a slow growing tumour in the pituitary gland. This tumour produces large amounts of the hormone ACTH. Adrenal-dependent Cushing’s disease This form of the disease occurs when a tumour producing a large amount of cortisol develops in one, and sometimes both, of the adrenal glands. The development of either of these tumours causes excessive release of cortisol into a dog’s bloodstream. Over time, the signs of Cushing’s disease will become more and more noticeable. Forms of Cushing’s disease Signs of Cushing’s disease Cushing’s disease is usually seen in older dogs. Small breed dogs and female dogs are more likely to develop the disease. Signs may be similar to those of normal ageing, so can sometimes be difficult to recognise. The most common signs include: l Increased thirst l More frequent urination, possible incontinence l Increased appetite l Pot belly l Thin skin l Hair loss and/or skin disease l Muscle wastage l Lethargy or weakness l Excessive panting Your dog may not necessarily show all of these signs. If Cushing’s disease is suspected, we will recommend a series of lab tests to confirm the diagnosis. As this can be a difficult disease to diagnose, several tests may need to be performed on blood and urine. These tests will determine how much excess cortisol is produced by the dog’s adrenal glands. Your dog will normally need to stay at the surgery for a few hours or the whole day whilst these tests are performed. We may also recommend an ultrasound scan of your dog’s abdomen to image the adrenal glands. Cushing’s disease causes hypertension and often loss of protein in urine. Both of these signs will be monitored closely. Once on medication for Cushing’s these signs may resolve but often need to be treated alongside it How is Cushing’s disease diagnosed? Treatment is given to reduce the level of cortisol in your dog’s blood, and will need to be given for the rest of your dog’s life. The aim of treatment is to slow Treatment of Cushing’s disease 04 small talk