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My 4 kg cat ate several wilted chrysanthemum petals that had been in a vase for a week — is mould making them more toxic?

Cats · Emergency guide

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

The mould itself adds risk, but the chrysanthemums are already toxic. Wilted petals still contain pyrethrins, which can cause drooling, vomiting, and in larger amounts, tremors. Mould may bring on additional vomiting or diarrhoea from stomach upset. Wash any plant sap off her muzzle with mild soap and water. Watch for wobbliness or twitching over the next 6-12 hours — if you see tremors, go to the vet immediately. For now, offer fresh water and keep her quiet.

Why is this dangerous?

Chrysanthemums, mums and many daisies contain pyrethrins and sesquiterpene lactones. Pyrethrins affect nerve sodium channels — the same target as permethrin flea treatments that are so dangerous to cats.

Most exposures cause only gut upset and skin irritation, but cats are more sensitive and larger amounts can cause tremors.

Why speed matters

Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.

Signs to watch for

  • Drooling, vomiting, diarrhoea
  • Skin redness, itching or rash on the muzzle and paws
  • Wobbliness, unsteady walk
  • Tremors or twitching in larger ingestions
  • Lethargy and loss of appetite

What to do right now

  1. Call your vet or a poison line with the amount and the pet weight.
  2. Wash the skin with mild soap and water if plant sap is on the fur.
  3. Keep cats away from cut flowers — they are far more sensitive to pyrethrins.
  4. Watch for tremors and go in if they appear.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

The step-by-step response, from the first minute to the vet visit, is in our Chrysanthemum & Daisy Family emergency guide.

Open the full emergency guide: Chrysanthemum & Daisy Family →