Quick Answer: The classic early signs of Cushing’s disease in dogs are increased thirst, increased urination, increased appetite, and excessive panting, according to the AKC, VCA Animal Hospitals, and PetMD. These build so gradually — the AKC puts it at “at least a year” before they’re obvious — that they’re frequently written off as normal aging until more visible signs appear: a pot-bellied abdomen, thinning skin, symmetrical hair loss, and recurrent skin or bladder infections. About 80-85% of cases come from a pituitary tumor, per VCA Animal Hospitals, and the standard treatment is a daily medication called trilostane, usually for life.
Cushing’s disease is one of the slower-building conditions on this site to catch, because nothing about the early symptoms says “something is wrong” in the way that vomiting or limping does. A dog that’s drinking more and seems hungrier all the time can look, day to day, like a dog that’s just being a dog.
Dog Cushing’s disease, by the numbers
- “At least a year” — how long it typically takes for Cushing’s symptoms to become obvious enough for owners to notice, per the AKC, which is also why the disease is so frequently missed in its early stages.
- 80-85% of natural Cushing’s cases are pituitary-dependent (a tumor on the pituitary gland), per VCA Animal Hospitals; the remaining 15-20% are adrenal-dependent, and roughly half of those adrenal tumors are malignant.
- 75% of dogs diagnosed with Cushing’s disease are female, per the AKC, and the condition mostly affects dogs under 44 pounds.
- Middle-aged to senior — PetMD notes Cushing’s primarily affects older dogs, with cases in puppies and young dogs uncommon.
Why the early signs get written off as “just getting older”
Increased thirst, more trips outside to urinate, a bigger appetite, more panting — the AKC, VCA Animal Hospitals, and PetMD all list these same four as the earliest and most consistent signs of Cushing’s disease. The problem is that every one of them has a dozen harmless explanations: warmer weather, more exercise, a diet change, or simply a dog getting older and slowing down. The AKC is direct about this — it takes “at least a year” for the pattern to become clear enough that an owner connects the dots, and by then the disease has usually progressed to something more visible.
| Sign | When it shows up | Commonly mistaken for |
|---|---|---|
| Increased thirst & urination | Early, gradual | Hot weather, more exercise |
| Increased appetite | Early, gradual | Growth, a food switch, "always hungry" personality |
| Excessive panting | Early, gradual | Heat, anxiety, being overweight |
| Pot-bellied abdomen | Later stage | General weight gain or obesity |
| Thin skin, symmetrical hair loss | Later stage | Normal aging, seasonal shedding |
| Recurrent skin/bladder infections | Later stage | A one-off infection, not a pattern |
The pot-bellied look deserves its own callout, because it’s easy to confuse with plain weight gain. VCA Animal Hospitals attributes it to weakened abdominal muscles and fat redistributing to the organs, not just fat under the skin — which is a different mechanism than the gradual, all-over weight gain covered in our dog obesity guide. A dog with Cushing’s can have a swollen-looking belly on otherwise thin limbs, while a dog that’s simply overweight tends to carry fat more evenly.
Digital Pet Water Fountain (Flow-Tracking)
- Doesn't diagnose anything, but a fountain that needs refilling noticeably more often than usual is a low-effort way to notice the gradual rise in water consumption that's one of the earliest Cushing's signs.
- Useful alongside a written log — jotting down roughly how often the reservoir empties week to week makes the "at least a year" slow build easier to actually catch, instead of relying on memory.
- Not a substitute for a vet visit if increased thirst shows up alongside any other sign on this page — a fountain only tells you drinking went up, not why.
Once a vet suspects Cushing’s, the diagnostic workup and the trilostane prescription that usually follows mean a lot of vet-recommended supplies arriving fast — try Amazon Prime free for 30 days so a specific food, supplement, or monitoring tool a vet suggests can show up in two days instead of a week.
The steroid look-alike vets want owners to know about
Not every dog with Cushing’s-like symptoms has a tumor. PetMD describes a separate condition called iatrogenic Cushing’s syndrome, caused by long-term corticosteroid medications like prednisone — often prescribed for allergies, autoimmune conditions, or a chronic problem like recurring ear infections that needs repeated oral steroid courses, the kind covered in our dog ear infection treatment guide. A dog on months of steroids can develop the same increased thirst, appetite, and pot-bellied look as naturally occurring Cushing’s, but from the medication itself rather than a pituitary or adrenal tumor.
The distinction matters for treatment. PetMD notes iatrogenic Cushing’s is typically reversible once a vet gradually tapers the steroid dose — no trilostane, no lifelong medication, no surgery. That’s a meaningfully different, generally easier path than the natural disease, which is why vets always ask about a dog’s medication history before assuming a tumor is the cause.
For dogs with a confirmed tumor, VCA Animal Hospitals puts the split at 80-85% pituitary-dependent versus 15-20% adrenal-dependent, and notes roughly half of adrenal tumors turn out to be malignant. Diagnosis typically involves bloodwork plus an ACTH stimulation test or a low-dose dexamethasone suppression (LDDS) test — VCA lists LDDS as the more commonly used of the two. PetMD lists trilostane (Vetoryl) as the preferred daily medication for pituitary-dependent cases, usually needed for life with periodic monitoring blood draws, while adrenal-dependent cases from a tumor directly on the gland may be candidates for surgical removal.
For owners already tracking a dog’s daily habits — see our best dog activity tracker roundup and PetPace collar review — a gradually declining activity trend that coincides with a thirstier, hungrier dog is worth flagging to a vet, even though no wearable can diagnose Cushing’s itself; that still requires bloodwork.
The bottom line
Cushing’s disease in dogs is a slow build, which is exactly what makes it easy to miss — the AKC’s “at least a year” timeline means the earliest signs (more thirst, more urination, more appetite, more panting) usually get chalked up to weather, age, or personality long before anyone thinks to mention them to a vet. The pot-bellied look, thinning skin, and recurrent infections that show up later are the signs that finally prompt a visit, but by then the disease has typically been present for a while. If a dog has been on long-term steroids for something like allergies or chronic ear infections, ask the vet whether iatrogenic Cushing’s — the reversible, medication-driven look-alike — could be the explanation before assuming the worst. Either way, a pattern of the early four signs together, rather than any single one in isolation, is the cue to get bloodwork done rather than waiting to see if it resolves on its own.