Pine Processionary Caterpillars and Your Dog
Every year, at the end of winter, we see dogs with swollen tongues and lots of drooling. The cause is usually the pine processionary caterpillar. It is small, but it can do serious harm very quickly.
What is the pine processionary caterpillar?
It is the caterpillar of a small night moth. It lives in white, silky nests in pine trees. You can spot them as white "cotton balls" at the ends of branches.
In Cyprus, usually from January to April depending on the weather, the caterpillars come down from the trees. They walk on the ground one behind the other in long lines, like a little train. That is exactly what makes dogs curious.
Why are they so dangerous?
Each caterpillar is covered in thousands of tiny hairs. These hairs release a toxin. When a dog sniffs, licks or bites a caterpillar, the hairs stick to the tongue, lips and mouth.
The reaction is very fast. In serious cases, the tongue can turn dark and parts of it can die. That is why every minute counts. Cats are rarely affected, but it can happen.
Signs to watch for
- Sudden heavy drooling
- Swollen tongue, lips or face
- Pawing at the mouth or rubbing the face on the ground
- Vomiting
- The tongue changes colour and looks darker
- Restlessness, crying or trouble eating
If you have been near pine trees and you see any of these, treat it as an emergency.
What to do straight away
- Protect your hands. Wear gloves if you have them. The hairs can cause a reaction in people too.
- Rinse the mouth gently. Pour plenty of clean water over the mouth and tongue. Do not rub, because rubbing breaks the hairs and releases more toxin.
- Go to a vet immediately. Call us on 22 015979. Our clinic works by appointment and has no 24-hour service, so outside our hours go straight to a 24-hour emergency clinic.
How to prevent it
- Avoid pine trees in the months when the caterpillars come down, especially in parks and wooded areas.
- Always use a lead. On walks, keep your dog on a lead so you can move them away quickly.
- Check your garden. If you have pine trees, look for white nests in the branches.
- Do not remove them yourself. Ask your municipality or a professional to remove the nests safely.
- Watch children too. They can also react if they touch the caterpillars.
After treatment
Most dogs that reach a vet quickly recover well. They may need medicine, soft food for a few days and a follow-up visit so we can check how the tongue is healing. We will explain exactly what to watch for at home.
Common questions
Are empty nests dangerous too?
Yes. The hairs stay in the nests and on the ground for a long time, even after the caterpillars have gone. So it is best not to let your dog dig or sniff under pine trees, especially in spring.
Can I give a home remedy?
No. Do not give human medicines and do not try to make your dog vomit. The only thing to do at home is rinse gently with water. Then go straight to a vet.
My dog only sniffed a caterpillar. Should I worry?
Even a sniff can bring hairs into the nose and mouth. If you see drooling, swelling or your dog rubbing its face, call us straight away. If you are not sure, it is always better to ask.
What if a caterpillar only touched the coat?
The hairs can stay in the coat and reach the mouth when your dog licks itself. Wear gloves and rinse the area with plenty of water. If you see any signs, come in for a check.
Sources and further reading
The facts in this article are based on guidance from international and European veterinary organisations.
Worried about your dog?
If your dog has touched a caterpillar, call us straight away. Outside our hours, go to a 24-hour emergency clinic without delay.
📞 22 015979This article is for information only and does not replace an examination by a vet. If you are worried about your pet, please contact us.