Cats can get Cushing’s disease, but it’s rare. While Cushing’s is extremely common in dogs, the incidence in cats is far lower, roughly comparable to rates seen in humans. When it does occur in cats, it tends to look different than the canine version and carries a high risk of concurrent diabetes.
Why It’s So Uncommon in Cats
Cushing’s disease, also called hyperadrenocorticism, happens when the body produces too much cortisol over a prolonged period. In about 80% of affected cats, the cause is a small tumor on the pituitary gland (a pea-sized structure at the base of the brain) that signals the adrenal glands to overproduce cortisol. The remaining 20% of cases stem from a tumor on one of the adrenal glands themselves, and roughly half of those adrenal tumors are malignant.
Veterinary researchers still don’t fully understand why cats develop Cushing’s so much less often than dogs. One practical consequence of its rarity is that many vets have limited experience diagnosing it, which can delay recognition.
Steroid Medications as a Trigger
Cushing’s doesn’t always arise from a tumor. Cats that receive corticosteroid medications for allergies, inflammatory bowel disease, or immune-related conditions can develop an iatrogenic (drug-induced) form. This has historically been considered very rare in cats, with only a handful of published cases. However, at least one cat developed the condition after just four weeks of weekly steroid injections at a standard dose for stomatitis, a type of severe mouth inflammation. That’s a surprisingly short window, and it suggests that even relatively brief steroid courses carry some risk in susceptible cats.
Signs That Set Feline Cushing’s Apart
Some symptoms overlap with what dogs experience: increased thirst and urination, a ravenous appetite, and muscle wasting. But the hallmark sign in cats is something rarely seen in dogs: extreme skin fragility. More than half of cats with Cushing’s develop skin so thin and fragile that it tears or bruises during normal handling, routine veterinary exams, or even light contact. Wounds can appear seemingly out of nowhere.
Other skin changes include hair loss, darkened patches of skin, blackheads, and recurring abscesses. A cat with unexplained skin tearing, especially alongside increased drinking or a potbellied appearance from muscle loss, should be evaluated for Cushing’s.
The Diabetes Connection
Perhaps the most important thing to know about feline Cushing’s is its tight link to diabetes. An estimated 80 to 90% of cats with Cushing’s disease also develop diabetes. Cortisol directly interferes with insulin’s ability to regulate blood sugar, so chronically elevated cortisol levels push most affected cats into a diabetic state.
This connection works in reverse as a diagnostic clue, too. If your cat has diabetes that’s unusually difficult to control, resisting normal doses of insulin, Cushing’s disease is one possible explanation. In some cats, successfully treating the Cushing’s brings the diabetes into remission because the underlying hormonal disruption was the primary driver.
How Vets Diagnose It
Diagnosing Cushing’s in cats is more challenging than in dogs. The most commonly used screening tool, the ACTH stimulation test, measures how the adrenal glands respond to a hormone that tells them to produce cortisol. In cats, this test catches only about 56% of true cases, meaning it misses nearly half. Its specificity is better, around 86 to 89%, so a positive result is fairly reliable, but a negative one doesn’t rule Cushing’s out.
Because no single test is definitive, vets typically combine blood work, urine tests, and imaging (ultrasound of the adrenal glands or advanced imaging of the pituitary gland) to build a complete picture. The process can take time, especially when diabetes is already in the mix and complicating the hormonal readings.
Treatment and What to Expect
The primary medical treatment for feline Cushing’s is trilostane, a drug that blocks cortisol production. Cats typically start at about 1 mg per kilogram of body weight, given with food two to three times daily. That dosing schedule is more demanding than the once- or twice-daily routine used in dogs, partly because standard capsule sizes require more frequent doses to hit the right therapeutic level. Regular monitoring and dose adjustments are essential, since too much suppression of cortisol can be dangerous.
For the 20% of cats whose Cushing’s is caused by an adrenal tumor, surgical removal of the affected gland is an option. Surgery can be curative when the tumor is benign, but it carries real risks, particularly because these cats often have fragile skin that complicates wound healing and concurrent diabetes that requires careful perioperative management.
Prognosis With and Without Treatment
Without treatment, the outlook for cats with Cushing’s is poor. The combination of uncontrolled cortisol, progressive muscle wasting, fragile skin prone to infection, and often unmanageable diabetes leads to a declining quality of life.
With treatment, the picture improves substantially. One study of 15 cats treated with trilostane found a median survival time of 617 days, with some cats living beyond three and a half years. Skin fragility gradually improves as cortisol levels normalize, and diabetic cats may need less insulin or achieve remission entirely. The early weeks of treatment tend to require the most veterinary visits for monitoring, but many cats stabilize into a manageable routine.