Is Topical creams (5-FU, calcipotriene, hormone creams) toxic to cats?
No. Some prescription creams — fluorouracil (5-FU) for skin cancer, calcipotriene for psoriasis, and hormone creams (HRT, testosterone) — are severely toxic to cats who lick them from human skin.
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Key facts
- Verdict: No — dangerous to cats. Topical creams (5-FU, calcipotriene, hormone creams) should never be given deliberately.
- Category: Human prescription
- Onset: Signs can start 0–4 hours — see the full timeline below.
- If it's already happened: Call your vet now, or the Animal PoisonLine on 01202 509000 (24/7, charges apply) — see the emergency steps below.
If your cat has just eaten topical creams (5-fu, calcipotriene, hormone creams)
- Wipe any visible cream from the cat's fur or mouth.
- Call your vet immediately — these exposures are high-risk even from small amounts.
- If you can't reach your vet, call Animal PoisonLine (01202 509000) — paid triage, 24/7.
- Bring the prescription tube or a photo of the ingredients.
What's the full picture?
5-fluorouracil (5-FU, trade names Efudix and Fluoroplex) is used for certain skin cancers. A single lick from a treated skin area has caused feline deaths. Symptoms appear within hours — seizures, vomiting, bloody diarrhoea.
Calcipotriene (Dovonex) is used for psoriasis. A small amount licked can cause life-threatening rises in calcium.
Hormone creams (HRT, testosterone gels) can cause significant endocrine disturbance in pets exposed to them — keep cats away from recently applied hormone creams.
If you use any prescription topical, wash hands thoroughly after application, cover the treated area, and don't let a cat lick or rub against it.
Symptoms to watch for
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Cat owner essentials
For prescription-strength flea, tick and wormer protection, Best Vet Care ships direct from licensed vets — no vet visit required. (affiliate link)
A lockable medicine box is the simplest way to keep human tablets out of reach of a curious cat.
Recommended for cat owners
Related
Sources referenced for this guidance
- Veterinary Poisons Information Service (VPIS) — UK clinical toxicology reference used by vets
- International Cat Care — feline-specific clinical guidance
- BSAVA — British Small Animal Veterinary Association reference materials
- Merck Veterinary Manual — professional veterinary reference
About this guidance
Every entry on this site is compiled from published UK veterinary toxicology sources — International Cat Care, Veterinary Poisons Information Service (VPIS) references, RCVS-registered practice materials, and peer-reviewed feline medicine literature. Where the evidence is mixed, we err on the cautious side because cats are unusually sensitive to many common substances that are harmless to humans and even to dogs.
This is general information written for UK cat owners. It is not personalised veterinary advice for your specific cat, their age, weight, medical history, or the exact exposure you're dealing with. If your cat has eaten something or is unwell, call your vet first. The Animal PoisonLine on 01202 509000 is available 24/7 for a small fee and can tell you whether an emergency visit is needed.
Entries are reviewed and updated as new research emerges. Spotted an error? Let us know — corrections are investigated and applied within 24 hours. For more context on how we work, see about and our full disclaimer.
Last reviewed: · By the What Can My Cat Eat? editorial team