Steroid dosing and tapering in cats: from tablet maths to the last dose
With steroids, coming down takes longer than starting. The first 2-4 weeks put the disease out. The months after are spent finding "how little will keep it out". This article covers tablet maths, a step-down table, every-other-day dosing and stopping safely, with numbers.
- When steroids are first prescribed: what they are and why cats tolerate them
- Dosing and tapering: from tablet maths to the last dose (you are here)
- Side effects: diabetes, heart and liver, and when to check what
- Injections, tablets, inhalers and creams: the form is half the story
- When there is another disease: heart, diabetes, kidneys, infection
- Dose = ideal weight x mg/kg. If you need less than a quarter of a 5 mg tablet (1.25 mg), use a compounded product.
- A common taper: once signs are controlled, cut 25-50% every 2-4 weeks. These numbers come from reviews and practice, not from trials. Treat them as a starting point.
- Maintenance is often every other day. In 37 cats with pemphigus the median maintenance dose was 1.2 mg/kg per week (for 4 kg, 4.8 mg a week, a little more than 1.25 mg every other day) (Simpson 2013).
- Just 16 days at 2 mg/kg suppressed the adrenal response, and 6 of 7 cats had recovered 2 weeks after stopping (Middleton 1987). Cats recover quickly, but taper in steps anyway.
- Before each step down, decide your relapse numbers. If the cat relapses, go back one step to the last dose that worked.
| Who | Decides |
|---|---|
| At home | Splitting and giving the dose accurately, recording relapse signs at each step (vomiting, stool, cough, itch, weight), noting missed doses |
| Together | When to start tapering and by how much, which dose to return to after a relapse, whether to stop or stay on the lowest dose |
| The clinic | Adding another immunosuppressant (chlorambucil, ciclosporin) when relapses repeat, testing adrenal function if suspected after stopping |
1. Working out your cat's dose
Start with what each piece of a 5 mg tablet means in mg/kg for different weights. Find your cat's piece and you know which tier it is on.
| Piece of a 5 mg tablet | 3 kg | 4 kg | 5 kg |
|---|---|---|---|
| 1.25 mg (1/4 tab) | 0.42 | 0.31 | 0.25 |
| 2.5 mg (1/2 tab) | 0.83 | 0.62 | 0.50 |
| 5 mg (1 tab) | 1.67 | 1.25 | 1.00 |
| 7.5 mg (1.5 tabs) | 2.50 | 1.88 | 1.50 |
| 10 mg (2 tabs) | 3.33 | 2.50 | 2.00 |
Values in mg/kg. Anti-inflammatory tier 0.5-1, immunosuppressive tier 2-4 (article 1).
- Use ideal weight for overweight cats. At the same mg/kg, overweight cats had about twice the blood level (Center 2013).
- Halves along the score line are fairly accurate, but quarters vary a lot in size. Use a pill cutter, and ask for a compounded capsule or liquid if you need less.
- Prednisolone is very bitter. Many cats drool or foam if the bare tablet touches the tongue. Put it in an empty gelatin capsule or wrap it in a treat.
2. Tapering: an example step table
Take a 4 kg cat with gut inflammation started at 2 mg/kg (7.5 mg a day, 1.5 tablets). Below is an example built at a commonly used pace. Real timings depend on the disease and the response.
| Step | Dose | mg/kg | Duration | Move on when |
|---|---|---|---|---|
| 0 · Start | 7.5 mg daily (1.5 tabs) | 1.9 | 2-4 weeks | Signs controlled, plus 2 more weeks |
| 1 | 5 mg daily (1 tab) | 1.25 | 2-4 weeks | No relapse signs |
| 2 | 2.5 mg daily (1/2 tab) | 0.63 | 2-4 weeks | No relapse signs |
| 3 | 2.5 mg every other day | 0.31 (daily average) | 2-4 weeks | No relapse signs |
| 4 | 1.25 mg every other day (1/4 tab) | 0.16 (daily average) | 4+ weeks | Decide: maintain here, or stop |
- Relapse after a step down (e.g. vomiting rises to 2+ times a week, or weight drops more than 5% in 2 weeks): go back to the last dose that worked for 2-4 weeks. Next time, halve the step (e.g. alternate 2.5 mg and 1.25 mg instead of dropping straight to 1.25 mg every other day).
- Two relapses at the same step: the step above may be this cat's lowest effective dose. Stay there, or discuss adding another immunosuppressant to spare the steroid (article 5).
- 4 weeks at the last step with no relapse: decide whether to stop or continue at the lowest dose. In the pemphigus study 14% of cats eventually stopped, and 67% were maintained on prednisolone alone (Simpson 2013).
3. Why every other day?
With daily steroids, the body decides it no longer needs to make its own cortisol and the adrenal glands rest. The theory behind every-other-day dosing is that the drug-free day gives them a chance to work again. Prednisolone leaves the blood quickly (half-life about 0.9 hours in cats, Del Sole 2013), but its effect lasts much longer, so inflammation stays suppressed on alternate days.
To be honest, no study has compared daily vs every-other-day dosing in cats. The theory comes from people and dogs. It is still common for long-term maintenance because halving the total dose works for most cats.
4. Stopping: how fast do the adrenals recover?
| Study | Treatment | Adrenal suppression | Recovery |
|---|---|---|---|
| Middleton 1987 | Prednisolone 2 mg/kg or more, 16 days (7 cats) | From day 8, worse by day 15 | 6 of 7 recovered 2 weeks after stopping (day 30) |
| Crager 1994 | High-dose methylprednisolone, 1 week (8 cats) | Cortisol suppressed after 1 week | Recovered 1 week after stopping |
| Lien 2006 | Long-term steroids, iatrogenic Cushing's (12 cats) | Skin and muscle wasting, transient diabetes | Signs resolved a mean 4.9 months after withdrawal |
After short courses, cat adrenals recover fast. Still, Middleton's group advised against abrupt withdrawal even after one week (Middleton 1987). There is a case of a cat whose adrenal function failed after long-term injections, with high calcium and diabetes together. With steroid replacement both resolved within 9 weeks (Smith 2002).
5. Missed doses and vomiting
- Noticed on the same day? Give it when you remember and go back to the usual time the next day. Noticed the next day? Give only that day's dose. Never give a double dose.
- Vomited soon after and you can see the tablet? You can give it again. Prednisolone peaks in the blood about 1 hour after dosing (Del Sole 2013), so if vomiting happens after an hour, most of it has been absorbed. Wait for the next scheduled dose.
- On every-other-day dosing, mark the "dose days" on a calendar or in the app medication log. Alternate days are the easiest schedule to miss.
6. Where opinions differ
6-1. How fast should you taper?
Why it divides people: side effects, especially diabetes, cluster in the first 3 months at high doses (article 3), which argues for a fast taper. But 7 of 10 cats with lower-airway disease still had airway inflammation after their signs had gone (Cocayne 2011). Taper too fast and the disease returns, and a relapse means starting again at high doses.
Our view: keep the starting dose for 2 weeks after signs are controlled, cut by 25-50%, and go slowly over the last two steps (4+ weeks). For cats at high diabetes risk (obesity, glucose in the urine before starting) we would agree an earlier first step down.
Checking it in your cat: record the relapse numbers for 2 weeks at each step and compare with the step before.
6-2. Is the goal to stop, or to stay on the lowest dose?
Why it divides people: diseases that relapse often, such as lymphoma or pemphigus, may need high doses again if the drug is stopped. Allergy or asthma can sometimes be stopped after a change of season or environment.
Our view: it depends on the disease. Where relapse is dangerous (immune-mediated anaemia, lymphoma), the default is staying on the lowest dose. Where relapse is easy to bring back under control (allergic skin), the default is trying to stop.
7. What to bring to the clinic
- A step-by-step log of dates, doses and relapse numbers. It is the basis for deciding the taper speed together.
- The dose at relapse and the dose before it, which shows roughly where the lowest effective dose is.
- Missed doses, to tell a taper relapse from a missed-dose relapse.
- The date of any planned surgery or anaesthesia during the taper.
8. Read next
- Article 1 · When steroids are first prescribed
- Article 3 · Side effects
- Article 4 · Injections, tablets, inhalers and creams
- Article 5 · When there is another disease
📌 One-line tip: decide "above this number, it is a relapse" before each step down. Without a threshold, relapses are noticed late.