This disease, also known as Cushing syndrome, is the most common endocrine disease in dogs and it is due to excess cortisol in the body. This excess cortisol can be derived from dogs own body or it can be as a result of treatment from corticosteroid medications. Dogs with excess production of cortisol, 85% of them have pituitary gland tumors and the 15% have adrenal gland tumors. In addition, it has been observed that 13.61% of dogs with hyperadrenocortism will also have diabetes mellitus. This disease normally affects middle to old aged dogs from 7- 12 years.
Symptoms of Cushing disease include increased thirst and urination, and this is the most common sign in 80 % of the cases. Other symptoms include increased appetite, obesity, pot belly with visible veins on the thin skin, recurrent skin and ear infections, muscle weakness and lethargy.
Diagnosis of Cushing disease is based on the clinical signs, laboratory tests and diagnostic imaging. It is important for the veterinarian to know the causes of excess cortisol, especially if it is from endogenous origin, and differentiate Cushing from the pituitary or adrenal disease. This will enable veterinarians to formulate the most appropriate treatment protocol and determine an accurate prognosis.
Dogs with cushing disease are more commonly treated with drug therapy like Ketoconazole, Trilostane and l-Deprenyl. Surgery is indicated in patients with adrenal tumors in the absence of predetermined complicating factors like uncontrolled diabetes mellitus. However, development of diabetes mellitus in dogs with Cushing disease presents poor prognosis.