Prednisolone Dosage for Cats Calculator

This free prednisolone dosage for cats calculator shows the published weight-based dose range — the anti-inflammatory and immunosuppressive tiers — and converts a vet-prescribed dose into tablets or mL. It also helps you check a dose, picture a safe taper and read side effects.

Prednisolone is a prescription steroid, not a self-start medicine. Use this to understand or double-check a dose your vet has already prescribed. Two rules matter most: cats need prednisolone, not prednisone, and the dose must be tapered slowly, never stopped abruptly. Your vet sets the exact dose and taper.

See the published mg/day range for your cat’s weight and the condition tier your vet is treating.

Cat’s weight

Unit

Condition tier

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published daily range

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Low end

Per day

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High end

Per day

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Rate

mg per kg

Turn the dose your vet prescribed into tablets or millilitres.

Prescribed dose (mg)

Form

Tablet strength (mg) or liquid (mg/mL)

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to give per dose

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Prescribed

Dose mg

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Strength

Product

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Exact

Of product

Not sure if your vet’s dose looks normal? Compare it to the published ranges.

Cat’s weight

Unit

Vet’s prescribed dose (mg per day)

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where this dose sits

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Per kg

Daily

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Weight

In kg

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Prescribed

mg/day

Steroids must be stepped down, never stopped suddenly. See an example pattern (your vet sets the real one).

Current dose (mg per day)

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never stop abruptly

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Step 1

Starting

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Step 2

Reduce

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Step 3

Then EOD

Seeing a change on prednisolone? Check whether it’s expected or a reason to call the vet.

What are you seeing?

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what it usually means

Prednisolone Dosage for Cats, by Weight

The standard prednisolone dosage for cats depends on what is being treated and is worked out per kilogram of body weight. There are two published tiers: an anti-inflammatory dose of 0.5 to 1.0 mg/kg per day (for allergies, asthma and mild inflammation) and an immunosuppressive dose of 2.0 to 4.0 mg/kg per day (for autoimmune disease, IBD and lymphoma). So a 10 lb (4.5 kg) cat is usually in the region of 2.5 to 5 mg a day for the anti-inflammatory tier, or 9 to 18 mg a day for the immunosuppressive tier. These are reference ranges only: prednisolone is a prescription steroid, and your veterinarian sets the exact dose, how often it is given, and the taper for your individual cat.

Cat weight	Anti-inflammatory (0.5–1 mg/kg)	Immunosuppressive (2–4 mg/kg)
5 lb (2.3 kg)	~1–2.5 mg/day	~4.5–9 mg/day
8 lb (3.6 kg)	~1.8–3.6 mg/day	~7–14.5 mg/day
10 lb (4.5 kg)	~2.5–4.5 mg/day	~9–18 mg/day
12 lb (5.4 kg)	~2.7–5.4 mg/day	~11–22 mg/day
15 lb (6.8 kg)	~3.4–6.8 mg/day	~14–27 mg/day
20 lb (9.1 kg)	~4.5–9 mg/day	~18–36 mg/day

A common prescription is 5 mg once a day for an average cat, often stepped down over time. If you have a 5 mg tablet, the Tablet/Liquid tab shows what fraction a smaller dose needs.

How Long Does It Take Prednisolone to Work in Cats?

Prednisolone acts fast. For inflammation, itching, appetite and energy, many owners see a difference within 24 to 72 hours, and sometimes the same day. Conditions like asthma or IBD may take several days to a week or two to settle fully, and autoimmune disease is judged over weeks. If you have seen no improvement at all after a few days, contact your vet rather than increasing the dose yourself — the dose, the diagnosis, or the drug form (it must be prednisolone, not prednisone, in cats) may need review.

Prednisolone vs Prednisone in Cats

This matters more in cats than in dogs or people. Prednisone is a “pro-drug” that the liver has to convert into active prednisolone — and cats convert it poorly and unreliably. For that reason vets almost always prescribe prednisolone directly for cats, so it works without needing conversion. If your cat was given plain prednisone, or you are comparing a dog’s prescription, raise it with your vet. The milligram numbers for the two are treated as roughly equivalent, but the form is the point: give cats prednisolone.

Never Stop Prednisolone Abruptly

After more than a week or two of steroids, the body’s own adrenal glands wind down their natural cortisol production. If the drug is stopped suddenly, the cat can be left unable to make enough on its own, which is dangerous. That is why prednisolone is tapered — the dose is lowered in steps and often moved to every other day before stopping, giving the adrenal glands time to recover. The Tapering tab shows an example of the shape this takes, but the real schedule is always set by your vet based on the condition and how long your cat has been treated. Never skip the taper, and do not stop early just because your cat seems better.

Side Effects to Expect and to Watch For

The everyday effects are usually increased thirst, more urination and a bigger appetite — expected, and not alarming on their own. Keep water available and avoid letting your cat gain excess weight. The complications to take seriously are steroid-induced diabetes (especially in overweight cats, and the reason to watch for heavy thirst with weight loss) and secondary infections, because steroids dampen the immune system. Use the Side Effects tab to sort an everyday change from one worth a call. Cats with diabetes, heart disease, kidney disease or infections need extra caution, which is another reason the dose has to be a vet’s decision.

Frequently Asked Questions

How long does it take prednisolone to work in cats?

Often within 24 to 72 hours for inflammation, appetite and energy — sometimes the same day. Asthma and IBD can take several days to a week or two to settle. If there’s no change after a few days, call your vet rather than raising the dose.

What is the prednisolone dosage for cats by weight?

The anti-inflammatory range is 0.5 to 1.0 mg/kg per day and the immunosuppressive range is 2.0 to 4.0 mg/kg per day. A 10 lb (4.5 kg) cat is roughly 2.5 to 5 mg/day anti-inflammatory, or 9 to 18 mg/day immunosuppressive. Your vet sets the exact dose.

Is 5 mg of prednisolone a day a normal dose for a cat?

Yes, 5 mg once daily is a common starting dose for an average-sized cat, usually tapered down over time. For a 10 lb cat that’s about 1.1 mg/kg — the top of the anti-inflammatory range. Always follow your vet’s specific instructions and taper.

Why prednisolone and not prednisone for cats?

Cats convert prednisone to its active form, prednisolone, poorly and unreliably in the liver, so prednisolone is given directly. The milligram amounts are treated as roughly equivalent, but the form matters — cats should get prednisolone.

Can I stop my cat’s prednisolone suddenly?

No. After more than a week or two, stopping abruptly can cause an adrenal crisis because the body’s own cortisol production is suppressed. The dose must be tapered down in steps, often to every other day, on a schedule your vet sets.

What are the side effects of prednisolone in cats?

Commonly increased thirst, urination and appetite. The serious risks are steroid-induced diabetes (especially in overweight cats) and secondary infections, since steroids suppress immunity. Contact your vet for not eating, vomiting, signs of infection, or heavy thirst with weight loss.

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PetCalculatorHub Editorial Team

This calculator uses the widely published feline reference ranges for prednisolone: an anti-inflammatory dose of 0.5–1.0 mg/kg/day and an immunosuppressive dose of 2.0–4.0 mg/kg/day, with pound-to-kilogram conversion (÷ 2.2046) and tablet or liquid conversion from the strength you enter. These are general reference figures, not a prescription or a treatment plan. Prednisolone is a prescription corticosteroid; the correct dose, dosing frequency, every-other-day plan and taper depend on your cat’s condition, weight, other illnesses and response, and must be set and adjusted by your veterinarian. Never start, change or stop prednisolone on your own. The example taper is an illustration only.

For prednisolone guidance and steroid safety, see VCA Animal Hospitals and the Cornell Feline Health Center.

Last updated: October 2026