Steroid-Induced Cushing's Disease in Cats Explained
By Dr. Zubair Khalid, DVM, MS, PhD ·
Cushing's disease in cats from steroids happens when long-term or high-dose corticosteroid medications push cortisol levels too high, creating signs that mimic the natural disease. The key difference is that steroid-induced (iatrogenic) Cushing's is caused by medication you give, not by a tumor, so it can improve once the drug is reduced or stopped. This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Steroid-induced Cushing's in cats is caused by prescribed corticosteroids such as prednisolone, not by a pituitary or adrenal tumor [1].
- The most common signs are increased thirst and urination, a pot-bellied appearance, increased appetite, panting, muscle wasting, and skin or coat changes [1].
- Diagnosis starts with a full history of every steroid your cat has received, including injections, ear drops, and topical products.
- Never stop a long-term steroid suddenly. Tapering must be planned and supervised by your veterinarian.
- Most cats improve once the steroid dose is reduced or the drug is changed, but the process can take weeks to months.
What Is Steroid-Induced Cushing's Disease in Cats?
Cushing's syndrome is any disorder caused by elevated cortisol concentrations in the body [1]. In the natural form, a pituitary tumor produces too much ACTH, which tells the adrenal glands to release excess cortisol. That form is called pituitary-dependent hyperadrenocorticism, or Cushing disease, and it accounts for 80% to 85% of reported hyperadrenocorticism cases [1].
Steroid-induced Cushing's works differently. When you give a cat a corticosteroid medication, you are adding cortisol-like hormone directly into the body. Over time, high doses or long courses can produce the same outward signs as the natural disease. This form is often called iatrogenic Cushing's, meaning it is caused by medical treatment.
The distinction matters for your cat's care. Natural Cushing's in cats is uncommon and usually requires endocrine testing, imaging, and possibly lifelong medication or surgery [2]. Steroid-induced Cushing's is far more common in cats because corticosteroids are widely prescribed for allergies, asthma, inflammatory bowel disease, and immune-mediated conditions. The treatment path is different too. For iatrogenic cases, the goal is to reduce or replace the offending steroid, not to remove a tumor.
Signs Owners Notice First
Cortisol affects nearly every body system, so the signs can appear gradually and be easy to miss at first. You may notice one or two changes before others become obvious.
The classic signs include:
- Drinking more water and urinating more often (polyuria and polydipsia) [1]
- A rounder, pendulous abdomen, sometimes called a pot belly [1]
- Increased appetite, sometimes demanding food constantly [1]
- Panting, even when your cat is resting [1]
- Muscle wasting, especially along the spine and hind legs [1]
- Skin changes such as thinning, poor hair regrowth, or a dull coat [1]
Skin fragility is a serious concern in cats with hyperadrenocorticism. One report described a cat with pituitary-dependent disease who developed multiple skin wounds with no known trauma, and the skin became so fragile that further lesions led to euthanasia [3]. If your cat's skin tears easily or wounds will not heal, that is a reason to call your veterinarian promptly.
Some cats with Cushing's syndrome also develop diabetes mellitus, and the two conditions can complicate each other. A case report of a 10-year-old Persian cat described polyuria, polydipsia, chronic dry seborrhea on the back and flanks, and lack of hair regrowth on the abdomen, with both Cushing's syndrome and diabetes confirmed by testing [4]. If your cat has diabetes that is hard to control, hypercortisolism may be part of the picture.
Causes and Risk Factors
The main cause of steroid-induced Cushing's in cats is therapeutic corticosteroid use. Prednisolone is one of the most commonly prescribed steroids in feline medicine, and it is also used long-term for hypoadrenocorticism replacement in cats [5]. Any cat receiving repeated or high-dose steroids can develop signs, but some factors raise the risk.
Which Steroids and Routes Matter
It is not only oral tablets. Injectable steroids, long-acting depot preparations, ear medications, eye drops, and even some topical skin products can be absorbed enough to affect the whole body. When your veterinarian takes a history, they need to know about every product your cat has received, including ones prescribed by another clinic or given without a prescription.
Dose and Duration
Higher doses and longer treatment courses increase the chance of signs. The exact threshold varies by cat, by the specific steroid, and by how it is given. There is no single dose that is safe for every cat, so your veterinarian calculates the dose from your pet's weight and health. If you want to understand how feline steroid doses are chosen, see Prednisolone for Cats: Feline Safe Steroid Dose and Autoimmune.
Natural Cushing's as a Separate Cause
Natural Cushing's in cats is uncommon and usually involves a pituitary tumor [6]. Adrenal tumors can also secrete cortisol, though this is less common [1]. These cases are not caused by medication, and they require different testing and treatment. Your veterinarian will consider both possibilities when evaluating your cat.
How It Is Diagnosed
Diagnosis starts with a detailed history and physical examination. Your veterinarian will ask about every steroid your cat has received, how long it was given, and at what dose. That history alone can point strongly toward a steroid-induced cause.
History and Physical Exam
Your veterinarian will look for the signs listed above, including body shape, coat quality, skin thickness, and muscle condition. They will also check for wounds or fragile skin, since skin fragility is an important complication in feline hyperadrenocorticism [3].
Blood and Urine Testing
Routine blood work and urinalysis help identify changes linked to high cortisol, such as high blood sugar or dilute urine. These tests also rule out other conditions that cause similar signs. A blood test before starting steroids can establish a baseline, which is why many veterinarians recommend it. For more on that, read What to Expect When Your Cat Needs a Blood Test Before Starting Steroids.
Endocrine Testing
If natural Cushing's is suspected, your veterinarian may run specific tests. Screening and diagnostic tests for hyperadrenocorticism include the urine cortisol:creatinine ratio, the ACTH stimulation test, and the low-dose dexamethasone suppression test [6]. In one reported feline case, a dexamethasone suppression test at 0.1 mg/kg helped confirm Cushing's syndrome alongside diabetes [4]. These tests are not perfect in cats, and results must be interpreted with the full clinical picture.
Imaging
If a tumor is suspected, computed tomography (CT) can help identify a pituitary mass. One cat with skin fragility had CT that revealed a pituitary mass consistent with pituitary-dependent hyperadrenocorticism [3]. Imaging is usually reserved for cases where natural disease is likely or where surgery or radiation is being considered.
| Feature | Steroid-Induced Cushing's | Natural Cushing's |
|---|---|---|
| Cause | Prescribed corticosteroids [1] | Pituitary or adrenal tumor [6][1] |
| Onset | During or after steroid treatment | Gradual, often in older cats |
| Key history | Steroid use is documented | No steroid exposure |
| Main treatment | Reduce or change the steroid | Medication, radiation, or surgery [6] |
| Reversibility | Often improves after tapering | Usually requires ongoing management |
Treatment Options
Treatment depends on whether the Cushing's is steroid-induced or natural. For steroid-induced cases, the central goal is to lower the amount of corticosteroid in your cat's body while still controlling the condition the steroid was treating.
Tapering the Steroid Safely
Never stop a long-term steroid suddenly. A cat's adrenal glands can become suppressed after prolonged steroid use, and an abrupt stop can cause a dangerous adrenal crisis. Your veterinarian will design a slow taper, often reducing the dose in small steps over weeks. The exact schedule depends on your cat's dose, how long it was given, and how they respond.
Switching or Replacing the Steroid
Sometimes the steroid can be changed to a different form or given every other day. In other cases, your veterinarian may add a non-steroidal medication to control the original problem, allowing the steroid dose to drop. If your cat has an immune-mediated or inflammatory condition, this balance takes planning. For background on how steroids are used in feline diseases, see Corticosteroid Therapy in Feline Diseases: Special Considerations.
Treating Natural Cushing's
If testing shows natural disease, treatment options include medical treatment, radiation, and surgery [6]. Trilostane is one medication used in cats. In one report, a cat with Cushing's syndrome and diabetes was treated with trilostane at 2 mg/kg by mouth twice daily along with insulin glargine, and blood glucose and cortisol concentrations stabilized [4]. Another report described two cats with Cushing's syndrome and diabetes treated with cabergoline at 10 μg/kg by mouth every 48 hours, with both cats achieving diabetic remission within 1 and 6 months [7]. These are specific cases, and your veterinarian will choose a plan for your cat.
Managing Complications
Diabetes, skin fragility, high blood pressure, and infections may need separate treatment. A cat with Cushing's syndrome and diabetes may need insulin adjustments as cortisol levels change [4]. Skin fragility requires gentle handling and prompt wound care [3].
Recovery, Outlook, and Long-Term Management
For steroid-induced Cushing's, the outlook is often good once the steroid dose is reduced. Signs such as increased thirst and urination may improve within weeks, while coat and skin changes can take months to resolve. Some cats need ongoing treatment for the original condition, so the goal is often the lowest effective steroid dose, not zero.
For natural Cushing's, the outlook depends on the cause and how well your cat responds to treatment. Cats with pituitary tumors may be managed with medication, radiation, or surgery [6]. Some cats with Cushing's syndrome and diabetes can achieve diabetic remission with appropriate treatment [7]. Long-term monitoring usually involves repeat blood work, hormone testing, and checks for diabetes or high blood pressure.
Skin fragility can persist even after cortisol levels improve. In one case, cutaneous fragility remained for a prolonged period despite stabilization of blood glucose and cortisol [4]. Handle your cat gently, keep their nails trimmed, and report any new wounds right away.
Prevention
The best prevention is careful, targeted use of corticosteroids. Ask your veterinarian about the lowest effective dose and the shortest reasonable course. If your cat needs long-term steroids, schedule regular checkups so early signs of cortisol excess can be caught before they become severe.
Keep a written record of every steroid your cat receives, including injections and topical products. Share that list with any veterinarian who treats your cat. If you notice increased thirst, a changing body shape, or skin problems, mention it at your next visit. Early recognition makes tapering easier and safer.
If your cat has a condition that requires long-term steroids, ask whether monitoring tests are appropriate. Your veterinarian can explain the risks and benefits for your cat's specific situation. For a broader look at feline Cushing's, see Feline Cushing Syndrome: Diagnosis and Management.
Limitations and When to Contact a Veterinarian
This article gives general information, but every cat is different. Your veterinarian needs to examine your cat and review their full medication history to make a diagnosis and set a safe plan.
Contact your veterinarian the same day if your cat:
- Drinks or urinates much more than usual
- Develops a swollen or pendulous belly
- Has skin that tears easily or wounds that will not heal
- Shows new weakness, especially in the hind legs
- Has poorly controlled diabetes despite insulin
Go to an emergency clinic now if your cat:
- Collapses or cannot stand
- Vomits repeatedly or has severe diarrhea
- Breathes rapidly or with effort
- Becomes unresponsive or has a seizure
Call your veterinarian before changing any steroid dose. A routine visit is appropriate if you notice gradual changes in thirst, appetite, coat, or body shape, or if your cat has been on steroids for more than a few weeks.
Frequently Asked Questions
Can prednisolone cause Cushing's disease in cats?
Yes, prednisolone and other corticosteroids can cause steroid-induced Cushing's signs when used long-term or at high doses. The medication adds cortisol-like hormone to the body, producing the same outward signs as natural disease [1]. This form is different from natural Cushing's, which is caused by a tumor [6].
How long does it take for steroid-induced Cushing's to improve in cats?
Improvement usually begins within weeks of lowering the steroid dose, but full recovery can take months. Thirst and urination often improve first, while coat and skin changes take longer. Your veterinarian will set the taper pace based on your cat's response and the original condition being treated.
Is steroid-induced Cushing's in cats reversible?
It is often reversible once the steroid dose is reduced or the drug is changed, though some cats need ongoing low-dose treatment for their underlying condition. Natural Cushing's is not caused by medication and usually requires long-term management [6]. Your veterinarian can tell you which type your cat has after testing.
What happens if I stop my cat's steroid suddenly?
Stopping suddenly can cause a life-threatening adrenal crisis because the adrenal glands may be suppressed. Never stop a long-term steroid without veterinary guidance. Your veterinarian will design a slow taper to let the adrenal glands recover safely.
Can a cat with Cushing's syndrome also have diabetes?
Yes, Cushing's syndrome and diabetes can occur together in cats, and each condition can make the other harder to control [4]. If your cat has diabetes that is difficult to regulate, ask your veterinarian whether hypercortisolism testing is appropriate. Some cats with both conditions can achieve diabetic remission with treatment [7].
Related Articles
- Feline Cushing Syndrome: Diagnosis and Management
- Prednisolone for Cats: Feline Safe Steroid Dose and Autoimmune
- Corticosteroid Therapy in Feline Diseases: Special Considerations
- What to Expect When Your Cat Needs a Blood Test Before Starting Steroids
- How to Tell If Your Dog's Increased Thirst Is a Sign of Cushing's Disease
- Equine Cushing's Disease (PPID): An Owner's Guide
References
- Cushing Syndrome (Hyperadrenocorticism) in Animals - Endocrine System. Merck Veterinary Manual.
- 2023 AAHA Selected Endocrinopathies of Dogs and Cats Guidelines. Journal of the American Animal Hospital Association, 2023.
- Skin fragility in a cat presenting with pituitary-dependent hyperadrenocorticism. JFMS open reports, 2023.
- Cushing's Syndrome associated with diabetes mellitus in a Persian cat: clinical features, diagnosis, and therapeutic management. Brazilian journal of veterinary medicine, 2026.
- Feline hypoadrenocorticism: Emerging insights into clinical features, diagnosis, and treatment. Schweizer Archiv fur Tierheilkunde, 2026.
- Cushing Disease (Pituitary-Dependent Hyperadrenocorticism) in Animals - Endocrine System. Merck Veterinary Manual.
- Pituitary tumour shrinkage and diabetic remission in two cats with Cushing syndrome treated with cabergoline. The Journal of small animal practice, 2026.