Cushing's Disease in Dogs: Symptoms, Diagnosis & Treatment

What Cushing's disease actually is

Cushing's disease — hyperadrenocorticism — is what happens when a dog's body makes too much cortisol, the hormone that handles stress, metabolism, and immune balance. In roughly 80–85% of dogs it starts with a tiny, usually benign tumor on the pituitary gland at the base of the brain, which keeps signaling the adrenal glands to overproduce. About 15% of cases come from a tumor on an adrenal gland itself. A third version is man-made: long-term steroid medication (prednisone and the like) can create the same overload, which is why you should never stop those drugs abruptly. It's mostly a disease of middle-aged and older dogs, typically around 7–12 years, and the pituitary form shows up more in smaller breeds — Poodles, Dachshunds, Yorkshire Terriers, Miniature Schnauzers, Boston Terriers, and Bichons among them.

The signs that point to Cushing's

Why one blood test can't confirm it

The slow-onset trap: Because the signs arrive over months and each looks like normal aging, plenty of dogs live with untreated Cushing's for a long time. If your senior dog is suddenly drinking and urinating much more, that alone is worth a vet visit — it overlaps with kidney disease, diabetes, and other treatable problems, so it's never something to just watch.

No single test: There's no one blood test that says "yes, Cushing's." Routine bloodwork often shows a raised liver enzyme (ALP) as a hint, but confirming it takes a dedicated hormone test — usually an ACTH stimulation test or a low-dose dexamethasone suppression test, each a small series of timed blood draws. Vets often add an abdominal ultrasound to tell the pituitary form from an adrenal tumor, because that changes the treatment plan. Testing takes a few hours and can't be rushed into a single needle stick.

When to see a vet — and the one treatment emergency

Cushing's itself isn't a sudden emergency, but the symptoms are your cue to book a workup rather than wait: any older dog with new heavy drinking, a bottomless appetite, a pot belly, or symmetrical hair loss deserves testing. The emergency to know comes after treatment starts. The medication (trilostane) lowers cortisol, and too much can drop it dangerously low — an Addisonian crisis. If a dog on trilostane suddenly won't eat, vomits, has diarrhea, seems very weak, wobbly, or collapses, stop the next dose and get to a vet or emergency hospital right away; this is treatable when caught quickly. That risk is exactly why treated dogs need regular monitoring rather than a set-and-forget prescription.

Typical US cost ranges

• Screening bloodwork and urinalysis: USD 150–300
• Confirmatory hormone test (ACTH stim or LDDST): USD 200–350
• Abdominal ultrasound (pituitary vs. adrenal): USD 300–600
• Trilostane (Vetoryl), per month: USD 40–150+ depending on dose and size
• First year of testing plus medication (small dog): roughly USD 1,500–2,500

Cushing's is a lifelong, managed condition rather than a one-time fix, so the real cost is the ongoing medication plus the recheck hormone tests — often several in the first months as the dose is dialed in, then a couple of times a year. It adds up, but treating it usually beats leaving it: untreated Cushing's raises the risk of diabetes, stubborn infections, high blood pressure, and dangerous blood clots. Ask your clinic for a written estimate that separates the diagnostic workup from the ongoing plan so there are no surprises.

Living with a dog that has Cushing's

Most dogs are treated with a daily oral medication — trilostane is the common choice in the US, and it works for both the pituitary and adrenal forms. It doesn't cure the underlying tumor, but it reins in the cortisol, and within a few weeks to months many owners notice the drinking, accidents, and constant hunger ease off, with the coat gradually filling back in. The trade-off is commitment: the dose is fine-tuned with follow-up hormone tests, given with food, and never stopped or doubled on your own. Adrenal tumors are sometimes removed surgically. With steady monitoring, many dogs live comfortably for years after diagnosis, so the goal is good day-to-day quality of life, not a race to a cure.

Track the signs with PetCare AI

Cushing's is diagnosed and monitored partly by patterns you can log at home. Use PetCare AI to track how much your dog is drinking, bathroom accidents, appetite, coat changes, and energy over time — the kind of trend that's hard to judge day to day but tells a clear story across weeks. Ask the AI vet assistant something like "My 11-year-old dog is drinking a lot more and getting a pot belly — could it be Cushing's?" to understand what to expect before your visit, and use the in-app finder to locate a nearby clinic. PetCare AI can't diagnose Cushing's — that needs your vet's hormone tests — but a clear record makes the workup faster and the follow-ups easier.