If you have been filling up your dog’s water bowl more often and he has been begging for more food and crying to venture outside more frequently, your veterinarian may recommend running some blood panels on your furry friend. In light of these symptoms, one possible condition that he will likely check for is Cushing’s disease, one of the most commonly diagnosed diseases to affect the canine endocrine system.
What Is Cushing’s Disease?
The glands throughout your dog’s body that produce and regulate hormone levels make up his endocrine system. The three most commonly diagnosed endocrine diseases in dogs are diabetes, hypothyroidism and Cushing’s disease. Cushing’s disease is the result of malfunctions in the pituitary gland, located at the base of the brain, and the adrenal glands, which are situated on top of the kidneys. Usually caused by either pituitary or adrenal tumors, the pituitary gland sends incorrect messages that prompt the adrenal glands to produce excess amounts of the hormone cortisol. This cortisol is stored in the adrenal glands to be released as adrenaline during times of stress. The overproduction that occurs with Cushing’s disease throws your dog’s body into a constant state of stress, which can take a toll on your furry friend.
Cushing’s disease is gradual in onset and typically strikes dogs over 5 years of age. Dogs with Cushing’s disease show increases in drinking and urination. A ravenous appetite may also be present. Your dog may have a pot-bellied physique, and his coat may be thinning. Muscle weakness will show as lethargy and reluctance to engage in the physical activities that your canine companion used to enjoy. Another common symptom that you may notice is excessive panting. On examination, your veterinarian may detect high blood pressure, which often accompanies Cushing’s disease. Once you notice any of the symptoms, seek an evaluation from your veterinarian. Left untreated, Cushing’s disease can result in diabetes, calcium oxylate bladder stones and pulmonary embolism.
The first step in diagnosing your dog’s symptoms is for your vet to run a blood chemistry profile. This rules out other conditions, such as diabetes and kidney disease. Certain abnormal levels will also point toward the possibility of Cushing’s disease. From there, your veterinarian will recommend one of the specialized blood tests, such as the ACTH stimulation or a dexamethasone suppression test, to confirm the diagnosis. Other diagnostics may include imaging procedures, such as ultrasound, MRI or CAT scan, to look for abnormalities of the affected glands. These tests will also enable your veterinarian to determine whether a tumor is located on the pituitary gland or on an adrenal gland so that an effective course of treatment can be instituted.
The majority of Cushing’s disease patients have a pituitary gland tumor. It is most often a slow-growing adenoma, and surgical removal is rarely recommended for dogs due to the pituitary gland’s inaccessible location. Pituitary Cushing’s disease can be treated with long-term, oral medications that work by reducing the amount of cortisol production. Adrenal Cushing’s disease can also be managed with medications, but surgery may be indicated in some cases since roughly half of the adrenal tumors are known to be malignant. Once your dog begins medication, the periodic blood tests that your veterinarian recommends thereafter are imperative to maintain healthy levels and prevent Addison’s disease, the opposite condition of Cushing’s disease. As long as cortisol levels are properly regulated, your dog will likely enjoy several more years with your family.