Cushing's Disease in Dogs: Symptoms, Diagnosis & Treatment
It usually creeps in slowly. A ten-year-old dog starts emptying the water bowl twice as fast, asks to go out at 3 a.m., begs like she's never been fed, and grows a soft, sagging belly while the hair on her flanks thins out. Each change on its own looks like ordinary aging — together, they're the textbook picture of Cushing's disease. It's one of the more common hormonal disorders in senior dogs, it's very manageable when caught, and the frustrating part is that a single quick blood test can't confirm it. Here's how to recognize it, how vets actually diagnose it, what treatment involves, and what it costs in the US.
Cushing's disease (hyperadrenocorticism) is when a dog's body makes too much cortisol, most often from a small, usually benign pituitary tumor (about 80–85% of cases) and less often from an adrenal tumor (about 15%). It mainly affects middle-aged and older dogs, roughly 7–12 years. The classic signs are increased thirst and urination (often with new indoor accidents), a bigger appetite, a pot belly, thinning symmetrical hair loss, panting, and repeat skin or bladder infections. No single blood test confirms it — vets use a dedicated hormone test like an ACTH stimulation or low-dose dexamethasone suppression test, often plus an ultrasound. It's usually treated with a daily medication (trilostane) and lifelong monitoring; the condition is managed rather than cured. See a vet promptly if a senior dog develops these signs, and treat it as an emergency if a dog already on trilostane stops eating, vomits, has diarrhea, is very weak, or collapses.
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
| Sign you might notice | What's driving it | What to do |
|---|---|---|
| Drinking and peeing far more (indoor accidents) | Excess cortisol — usually the first thing owners notice | Ask your vet to screen; don't write it off as age |
| Constant, ravenous hunger | Cortisol ramps up appetite | Mention it alongside the other changes |
| Pot-bellied, sagging abdomen | Fat shifts to the belly + weakened muscle wall | A classic look — worth a full workup |
| Thinning hair on both flanks, thin skin | Cortisol's effect on skin and coat | Exam plus bloodwork and urine tests |
| Heavy panting, low energy, hind-leg weakness | Muscle wasting and metabolic strain | Workup; also rule out heart and lung causes |
| Repeat skin or bladder infections | High cortisol quietly suppresses the immune system | Flag the recurring pattern to your vet |
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.
Frequently asked questions
What are the first signs of Cushing's disease in dogs?
The earliest and most common sign owners notice is a big jump in thirst and urination, often with new accidents indoors. A ravenous appetite, a developing pot belly, panting, and thinning hair on both sides of the body usually follow. Because these come on slowly in older dogs, they're easy to mistake for normal aging.
How is Cushing's disease diagnosed?
There's no single blood test that confirms it. Routine bloodwork may hint at it (often a raised liver enzyme), but diagnosis needs a dedicated hormone test — usually an ACTH stimulation test or a low-dose dexamethasone suppression test, each involving timed blood draws. An abdominal ultrasound is often added to tell the pituitary form from an adrenal tumor.
Is Cushing's disease in dogs treatable?
Yes. Most dogs are managed with a daily oral medication, commonly trilostane (Vetoryl), which lowers cortisol and eases the symptoms over weeks to months. It controls rather than cures the disease, so it's given long-term with regular monitoring. Adrenal tumors are sometimes removed surgically.
How much does it cost to diagnose and treat Cushing's in the US?
Screening bloodwork and urine tests run about USD 150–300, the confirmatory hormone test USD 200–350, and an ultrasound USD 300–600. Trilostane costs roughly USD 40–150+ a month depending on dose and size. Counting the recheck tests, the first year often totals around USD 1,500–2,500 for a small dog.
Can Cushing's medication be dangerous?
It can if the dose lowers cortisol too far, causing an Addisonian crisis. If a dog on trilostane suddenly won't eat, vomits, has diarrhea, is very weak or wobbly, or collapses, stop the next dose and get to a vet right away — it's treatable when caught quickly. This is why treated dogs need regular monitoring rather than a set-and-forget prescription.
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