Cushing's syndrome happens when your dog’s body makes too much of a hormone called cortisol. This chemical helps him respond to stress, control his weight, fight infections, and keep his blood sugar levels in check. But too much or too little of it can cause problems.
Cushing’s, which is also known as hypercortisolism and hyperadrenocorticism, can be tricky for a vet to diagnose, because it has the same symptoms as other conditions. The key is to let your vet know about anything that’s different about your pet.
Estrus, or heat, is the stage in a female dog's reproductive cycle during which she becomes receptive to mating with males. At this time, estrogen levels first increase and then sharply decrease, and mature eggs are released from the ovaries. Ideally, your dog should be spayed before she enters her first heat cycle.
In some cases, surgery can cure dogs of the problem. If your pup can’t have an operation, he can take medicine to control his cortisol levels.
The condition mostly affects middle-aged and older dogs, and the warning signs may be harder to spot in the beginning.
You might notice your dog:
Is thirstier than usual
Pees more often. Housebroken dogs may have indoor accidents.
Loses hair or it seems slow to grow
Gets a pot belly
Has thinning skin
Seems very tired and inactive
Pants a lot
Gets skin infections
Types of Cushing's Syndrome
Many animals can get this condition. People can get it too.
There are two major types that affect dogs:
Pituitary dependent. This form is the most common, affecting about 80% to 90% of the animals who have Cushing's. It happens when there’s a tumor in a pea-sized gland at the base of the brain, called the pituitary.
Adrenal dependent: This type comes from a tumor in one of the glands that sit on top of the kidneys, called adrenal glands. About 15% to 20% of diagnosed dogs will have this type.
Another kind, called iatrogenic Cushing's syndrome, happens after a dog has taken steroids for a long time.
Getting Your Dog Diagnosed
There’s no method that’s 100% accurate for diagnosing Cushing's. So the vet will do a few tests to see what may be causing your pet's symptoms and to rule out other health problems.
Your vet will start by testing your dog’s blood and his pee. These exams can detect high cholesterol, diluted urine, urinary tract infections, or problems with a protein mostly found in the liver and bones called alkaline phosphatase. All of these are common in animals with Cushing’s. If the results show signs of the condition, your vet will follow up with hormone screening tests, such as:
ACTH stimulation test. It measures how well the adrenal glands work in response to a hormone, called ACTH, that usually prompts them to make cortisol. The vet will take blood samples before and after your dog gets a shot of ACTH to see how the hormone affected him.
Low dose dexamethasone suppression (LDDS) test looks at how your dog’s body works with a man-made version of cortisol, called dexamethasone. Blood samples before and after he gets a shot of the hormone help the vet see what’s going on.
If it seems like your pup could have Cushing’s, your vet might want to do an ultrasound scan of his belly. This imaging test will help her see if there’s a tumor on the adrenal glands. That could affect the kind of treatment he needs.