Household danger · 2 min read

Is Mothballs dangerous for cats?

No — dangerous

No — dangerous. Mothballs contain either naphthalene or paradichlorobenzene, both highly toxic to cats. A single mothball eaten by a 4 kg cat can be fatal. Still found in wardrobes, loft storage, and older UK houses.

If your cat has just eaten mothballs

  1. Move your cat away from the mothballs.
  2. Don't induce vomiting at home — this is dangerous in cats.
  3. Call your vet or out-of-hours emergency vet immediately.
  4. If you can't reach a vet, call the Animal PoisonLine on 01202 509000 — 24/7, charges apply.
  5. Note how much mothballs was eaten, when, and your cat's weight.

What's the full picture?

Naphthalene (the older type, with the strong moth-killing smell) is the more dangerous of the two mothball chemicals. Even a single naphthalene mothball can cause severe toxicity in a cat — symptoms include vomiting, tremors, seizures, and liver injury.

Paradichlorobenzene (the more modern 'white' mothball) is less acutely toxic but still causes vomiting, depression, and tremors. It's still a veterinary emergency.

Both types are sometimes found in UK attics, cupboards, and in stored clothing. They're sometimes mistaken for sweets by pets (and children). The smell is strong but doesn't always deter a curious cat.

Symptoms to watch for

0–12 hours
Vomiting, excessive drinking, tremors.
12–72 hours
Liver injury signs — jaundice, loss of appetite, collapse.

If you're worried right now

Call your vet or out-of-hours emergency vet first. For poison advice, the Animal PoisonLine (UK) is on 01202 509000 — 24/7, charges apply. Your vet can also call the Veterinary Poisons Information Service (VPIS) directly.

Bleach no Fertiliser caution Rat poison no Slug pellets no Tea tree oil no

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

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