Hyperadrenocorticism, also known as Cushing's disease, usually affects senior canines. Since it progresses gradually, it's possible your dog has had the condition for some time before he is diagnosed. Your dog will require treatment for the rest of his life. It's fair to say that his life expectancy -- if diagnosed in his golden years -- might not differ much from a dog of similar age who doesn't suffer from hyperadrenocorticism. Much depends on the type of hyperadrenocorticism affecting the dog.
Cushing's disease falls into two major categories. The first, known as "pituitary-dependent hyperadrenocorticism" occurs when your dog's adrenal glands produce too much cortisol and certain other hormones. About 85 percent of dogs with Cushing's are diagnosed with pituitary-dependent hyperadrenocorticism, which often involves a benign tumor on the pituitary gland. The second type results from tumors on the adrenal gland, either benign or malignant. This second type primarily impacts larger breeds.
Hyperadrenocorticism symptoms really run the gamut, affecting the entire metabolic system. Affected dogs usually experience excessive drinking and urination, along with hair loss, weight gain and urinary tract and skin infections. Other symptoms include constant hunger, exercise intolerance, potbelly formation, canine acne, changes in skin color and respiratory issues, including constant panting. Many of these symptoms also occur in canines with kidney and liver disease. Your vet will conduct various tests to make a diagnosis. In addition to ultrasounds or X-rays to locate tumors, your vet will perform the low-dose dexamethasone suppression test and the adrenocorticotropic hormone stimulation test.
Managing Cushing's Disease
Because dogs diagnosed with Cushing's are often older, your vet's primary concern might not revolve around your dog's life expectancy but his quality of life. You want your dog to remain as comfortable and symptom-free as possible. If your dog has a small or benign tumor, your vet might recommend surgery. Your vet also may prescribe medication that you must give your pet on a regular schedule for the rest of his life. Your vet will monitor your dog closely, so expect regular veterinary examinations and blood testing at a minimum of every three months.
Cushing's Disease Prognosis
Your dog's prognosis -- and his life expectancy -- depend on several factors. If his tumor is benign and small, his condition might be manageable for a long time. Larger or malignant tumors, or those affecting the brain, are another story. Dogs with these tumors generally have a poor prognosis and a short life expectancy.