Ronja the puppy waiting to go home

Pine Processionary Moth caterpillars can be extremely dangerous to dogs, cats and people

The arrival of the new year in the Algarve also brings the Pine Processionary Moth caterpillar problem. Completely harmless while in their nests in pine trees, when they descend from the trees, in their characteristic formations, to pupate underground, they can be extremely dangerous to dogs, cats and people.

The caterpillars’ hairs are intensely irritating and can cause an anaphylactic reaction (hives, closure of the airways, collapse – like a person with a severe peanut allergy). If a dog steps in some hairs, they will likely become rapidly distressed, licking their feet. Doing this, or sniffing at the caterpillar, will cause hairs to get in the mouth, making matters worse: the hairs can cause necrosis of the tongue, oesophagus, and stomach.

If not treated rapidly, exposure to Pine Processionary Moth caterpillars can prove fatal.

Last year, what could have been a catastrophe turned out to have a happy ending, due to owner foresight and quick thinking.

A dog-owning client was waiting for a company to remove many nests from their remote and rural property. The distribution of the nests made it impossible to guarantee the dogs could not get exposed. Removal had been scheduled for the next day.

I was asked what she should do if one of the dogs did happen upon a caterpillar…

My reply: “Wash the feet and mouth A LOT (citrus juice is best, but water is better than nothing). Don’t rub, just sluice. Inject the dog with adrenaline. Get it to us ASAP.”

The owner came to collect a syringe of adrenaline – I taught her how to perform an intramuscular injection using my own dog as a prop (sorry Maggie!).

Two days later, mid-Sunday morning, the phone rang … Ronja the Rafeiro puppy had picked up a stray leftover caterpillar, luckily within sight of her owner.

The phone call went like this: “Ronja got a caterpillar. I took it from her and washed her mouth with three lemons from my tree, gave her the injection, and we are in the car. She seems fine.”

When Ronja arrived, she looked so well I was even sceptical as to the type of caterpillar encountered. We placed an intravenous (IV) line to allow rapid fluid administration if she showed signs of anaphylactic shock, and dosed her with corticosteroids and antihistamines. By this point, about five minutes after arrival, a mild drool from her otherwise non-ulcerated, non-inflamed mouth had started. We gave her powerful opioids to soothe and allow her to lie on her side, and started washing her mouth.

She was irrigated with the juice of one orange and three lemons (what we happened to have to hand) and a litre of physiological saline.

She stayed with us until the next day, on her IV drip, being monitored, and went home as if nothing had happened. Lucky Ronja!

At this time of year, I recommend you avoid walking in pine forest areas, carry citrus juice just in case, and have the number of your vet stored in your phone.

By Dr Faye Campey
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Owned by British Vet Dr Faye Campey DVM BVetMed, 124Vet clinic is located in Cumeada. It boasts a spacious car park and easy access from the EN124 main road, between São Bartolomeu de Messines and Silves. Dra Faye takes pride in providing high quality, compassionate care.

Ronja the puppy waiting to go home

Dr Faye Campey
Pine Processionary Moth caterpillars