Pine processionary caterpillars in Málaga: a danger for dogs

The pine processionary is a caterpillar that moves across the ground in eye-catching nose-to-tail lines, as if in a procession. A curious dog finds them irresistible, and the consequences can be serious: contact with the mouth or tongue is a veterinary emergency.

When they appear around Málaga

The caterpillars spend the winter in the white, cotton-like nests you can see in pine branches. When they are fully grown, they come down the tree in a line to bury themselves in the soil.

Around Málaga this happens mainly between January and April. With winters getting milder, some years it starts earlier, even in December. Towns usually treat their pine trees in autumn: in August 2026, for example, Rincón de la Victoria treated around 700 pines.

Risk areas: parks and paths with pine trees, gardens and communal areas with pines, and wooded areas such as the Montes de Málaga or coastal pine groves.

Why they are so dangerous

The caterpillar’s body is covered in stinging hairs that come off easily and release a toxin. When a dog sniffs, licks or bites one, the hairs lodge in the mouth and tongue and cause severe swelling. Without quick treatment, part of the tongue can die off, and in serious cases the swelling can make breathing difficult.

The hairs also float in the air near the nests, so dogs can get eye or skin irritation without touching a caterpillar.

Warning signs

Sudden, heavy drooling.
A swollen tongue, or one that changes colour (bright red, purple or whitish).
Pawing at the mouth or rubbing it on the ground.
Vomiting, restlessness or obvious pain.
Difficulty breathing.

What to do if your dog touches one

Call your vet or go straight to an emergency clinic. This is a real emergency: the sooner it is treated, the better. At night, find a 24-hour emergency vet.
On the way, rinse the area with plenty of lukewarm water or saline, letting the water carry the hairs out of the mouth.
Don’t rub. Rubbing breaks the hairs and releases more toxin.
Protect your hands with gloves or a plastic bag: the hairs affect people too.
Don’t give food or water until a vet has seen your dog, unless they tell you otherwise.

How to prevent it

In season, avoid walks under pine trees, especially in the morning and on mild days.
Keep your dog on a lead in pine areas and watch what they sniff.
Check pines in your garden or development in autumn and winter. If you see nests, tell the town hall or a specialist company. Don’t try to remove them yourself.
Cats that go outside can also be affected, although it is less common.