Diagnosing Cushing’s

When your veterinarian suspects Cushing’s syndrome, they will perform blood tests to confirm the diagnosis. This usually starts with an overall health screen – these are more generalised tests where your vet will be looking for clues that Cushing’s may be present.

If the more generalised bloods raise your vet’s suspicion further, or if the signs your dog is displaying are indicative, Cushing’s specific tests will be performed to confirm or disprove the diagnosis.

As the cortisol concentration in the blood fluctuates greatly throughout the day in both healthy dogs and dogs with Cushing’s, diagnosis cannot be confirmed by just one measurement of cortisol. The two tests most commonly used to confirm diagnosis are the low-dose dexamethasone suppression test and the ACTH stimulation test. Your veterinarian will know which test is most suitable for your dog, however it is important to note that in some cases, it may be necessary to perform both tests.

Once initial tests have confirmed Cushing’s as the diagnosis, your vet may then discuss further tests to find out whether your dog has pituitary or adrenal disease. The decision to undertake these further tests will depend on the circumstances surrounding your pet individually.

The process of identifying the cause of the Cushing’s may involve further blood testing or further diagnostic imaging – including ultrasound, MRI or CT scanning.

Not every dog has their Cushing’s cause identified – however, consideration should be given to these tests as they may offer up alternative treatment options and/or provide an idea of prognosis for your pet.