Canine Cushing’s disease or hyperadrenocorticism is a disorder of the endocrine system resulting in the overproduction of the glucocorticoid hormones in the dog’s body. The endocrine system consists of the adrenal and the pituitary gland.
While the pituitary gland secretes the adrenocorticotrophic or the ACTH hormone, the adrenal gland secretes the cortisol hormones which in turn are responsible for fat metabolism and proper functioning of various organs such as the kidneys, the nervous system and the cardiovascular system.
The hormones are secreted in response to one another so if the corstisol levels are low the pituitary gland secretes more ACTH hormone and vice versa. The balance of these hormones is necessary for the proper functioning of the body. In Cushing’s disease this hormone balance is disturbed by either the pituitary or the adrenal gland secreting more hormones due to the presence of tumors in any of these organs.
Cushing’s disease is predominantly seen in middle aged and older dogs as the incidence of tumor increases with age. Moreover certain dog breeds like terrier dos. Labrador Retriever, Daschunds, poodles and boxers are prone to suffering from endocrine tumors.
The symptoms of Cushing’s disease are varied and can often be confused with other age related diseases in dogs. Some of the common symptoms of Cushing’s disease include excessive thirst, increased appetite, excessive urination, lethargy, weight gain or loss, bloating and a pot bellied appearance, weakness in legs, calcified lumps on skin and a dull coat. Since the disease weakens the immune system the dog may suffer from other diseases such as diabetes and pancreatitis.
Based on the medical history and the symptoms the veterinarian may diagnose the disease after a physical examination along with blood test, urine test, ultrasounds and CT scans. If the disease is confirmed then surgical intervention may be required to remove the tumor . Chemotherapy, medications and hormone treatment may be advised in certain cases.
However surgical intervention is usually not recommended in case of pituitary gland tumors. In such a case medications are administered to reduce the tumor. The treatment can be complicated in older dogs and dietary changes to include high protein and low purines and fats are often recommended for them.