When we bring a new puppy or an older dog into our home, we hope our trusted canine will live a long and healthy life — we quickly grow attached, and the dog becomes nothing less than a family member. A four-legged friend who shows serious signs of illness is a real worry, and you'll want to help your dog feel better to the best of your ability.
What Is Cushing's Disease In Dogs?
Cushing's disease is a condition in which the pituitary gland, a small organ at the base of the brain, discharges an excess of adrenocorticotropic hormone (ACTH). This, in turn, causes the production of too much cortisol. As cortisol plays an important role in the way the body processes protein, fat, and carbohydrates, as well as altering the immune response to inflammation, you can imagine that the condition would lead to some rather unpleasant symptoms. Also called hypercortisolism, Cushing's disease is far from the exclusive domain of dogs — humans can get it too, though not as frequently. 
Canine Cushing's disease is typically caused by a benign tumor of the pituitary gland (pituitary-dependent Cushing's disease), but can also be the result of a tumor of the adrenal gland (adrenal dependent Cushing’s disease). 
Cushing's Disease In Dogs: Symptoms You Should Watch Out For
Cushing's disease usually affects middle-aged or geriatric dogs, who are already at the stage of life when their health is declining. It comes with some unusual symptoms that are hard to ignore and will let you know that something is wrong with your dog, however. As a dog owner, you should look out for:
- Increased thirst: Your dog is drinking a lot more than before. This also means they'll be wanting to relieve themselves much more often, and will probably "bug" you for more frequent walks.
- Your dog's appetite will also increase, often resulting in a rotund, obese, dog.
- At the same time, your dog will be less active, resting more and just not having the energy they once did.
- Your dog's skin will be thinner and less healthy, prone to infections and the loss of a significant portion of their fur. Your dog will have a decidedly unwell look about them in time.
- Your dog will be panting more often. 
Cushing's disease sometimes "just happens", but some breeds — including the poodle, dachshund, beagle, boxer, and Boston terrier — are more likely to fall victim to Canine Cushing's disease. It can also be linked to the administration of the medications prednisone or dexamethasone for longer periods of time. 
I Think My Dog Could Have Cushing's Disease: What Now?
Symptoms like those of Cushing's disease clearly tell you that your dog is not well, and any time you are worried, a trip to the vet is warranted. Be aware that most dogs who are diagnosed with Cushing's disease do not live longer than two years from the time of diagnosis, with around 10 percent making it to four years. This is not necessarily because the disease kills, but because it's diagnosed in dogs who are already of "grandpa age". 
The diagnosis of Cushing's disease in dogs is quite complex, and therewith also pricey. The process may involve:
- A medical history, physical exam, and blood and urine tests to start off with.
- A complete white blood cell and platelet count test.
- A liver enzyme test.
- A blood sugar level test.
- An ACTH stimulation test.
- X-rays or ultrasound to try to locate the tumor. 
Cases of adrenal-dependent Cushing's disease in which the tumor has not spread can be treated surgically, thereby curing the dog. Most dogs will, instead, be prescribed medication or the rest of their lives, though. This will usually be Vetoryl (trilostane), the only medication that was FDA-approved to treat both kinds of canine Cushing's disease. This cannot be given to all dogs; if your dog also suffers from kidney disease, for instance, they will need another medication.
Other drugs that may be used to managed Cushing's disease in dogs include: