Diagnosis Of Cushing's Disease In Dogs

There are many diagnostic procedures that are used to obtain a positive veterinary diagnosis of a dog for Cushing's disease. Since the symptoms of Cushing's disease are relatively generic, and can also be symptoms of many other medical conditions, more than one of these diagnostic procedures may be done by a veterinarian.

CBC, Urinalysis, Blood Chemistry Panel

All of these three tests are usually recommended by a veterinarian. A CBC (complete blood count), urinalysis, and blood chemistry panel can all help detect certain abnormalities in your dog's body. Though not providing a definitive diagnosis, this may help your veterinarian to be able to form a positive diagnosis for Cushing's disease. The most common abnormalities detected in dogs with Cushing's disease are increased cholesterol, decreased kidney function, increased alkaline phosphate levels, and increased liver enzymes (more specifically, ALT).

Abdominal Ultrasound

This is another diagnostic procedure commonly used by a veterinarian when attempting to form a positive diagnosis for Cushing's disease. By using an ultrasound machine, a veterinary technician is able to study the size and shape of your dog's internal organs. Also, this ultrasound can be specifically used to examine the state of the adrenal glands.

Depending on which of the three types of Cushing's disease your dog has, the Adrenal glands may appear slightly different. If there is a tumor in the adrenal glands, one adrenal gland will typically appear abnormally shaped, or much larger than the other adrenal gland. If your dog has pituitary dependent hyperadrenocorticism, the adrenal glands will usually appear of normal size and shape during the ultrasound procedure.

Low Dose Dexamethasone Suppression Test

This is another very common diagnostic procedure that is used to positively diagnose a dog with Cushing's disease. In this procedure, the dog suspected of being afflicted with Cushing's disease is given several low doses of dexamethasone. After roughly an 8-hour period, the dog is tested for blood cortisol levels. Most healthy dogs that are not being affected by Cushing's disease will show an obvious decrease in blood cortisol levels when tested at this time.

However, if a dog has Cushing's disease, there will be no change in the blood cortisol levels even after being given the dexamethasone. This is a relatively accurate method for diagnosing Cushing's disease, since over 90% of dogs with Cushing's disease will have no response to the dexamethasone.

Urine Cortisol:Creatinine Ratio

This test involves the participation of a dog's owner, in order to be executed successfully. A dog's owner will collect a sample of their dog's urine at home. This is done outside the veterinary office, since the stress of being at the vet can cause fluctuations in the test results. Once the sample is collected, it is returned to the veterinary office, where it is then sent out to a special laboratory that will test the cortisol to creatinine ratio of the dog's urine.

If a dog is being affected by Cushing's disease, most of the time, the result will be abnormal. However, this is not a definitive diagnosis for Cushing's disease, because an abnormal cortisol to creatinine ratio can also be caused by several other medical conditions.