Can dogs and cats eat Processionary caterpillars?
Processionary caterpillars are covered in tiny barbed hairs containing an irritant protein. Dogs that sniff, lick or eat them can suffer severe tongue swelling and tissue death.
Why
Thaumetopoein (urticating protein in the caterpillars' hairs)
Signs to watch for
- sudden drooling
- swollen tongue, lips or face
- pawing at the mouth
- vomiting
- difficulty breathing
- tongue discolouration (later)
Good to know
Don't touch the caterpillars or nests yourself; rinse the mouth gently with water and go to the vet urgently. Oak processionary (T. processionea) occurs in Central Europe including Slovakia's neighbours and spreads with warming climate; pine processionary (T. pityocampa) is common in southern Europe (Spain, France, Italy, Croatia) — relevant when travelling with pets, especially in late winter/spring. Cats are less often affected but can be.
If you think your pet has been poisoned
If you suspect your dog or cat has eaten or touched something poisonous, contact your vet or the nearest emergency veterinary clinic immediately, even if your pet seems fine – some poisons take hours or days to show signs, and early treatment works best. Do not try to make your pet vomit unless a vet tells you to, as this can cause more harm. Take the packaging, label or a piece of the plant with you, and note what was eaten, roughly how much, and when.
Sources
Sources
- Blue Cross – Dogs, cats and toxic oak processionary moth caterpillars
- Turkish Journal of Veterinary & Animal Sciences – Tongue necrosis in a dog associated with the pine processionary caterpillar
Checked against these sources in October 2026.