The pine processionary which come from the pines, are highly toxic to our animals and refer to a very special consideration.

Regarding their biological cycle, it is very important to stress that, in late summer, we see the appearance of the butterflies that have remained buried in the soil (during the chrysalisation process, which is the pre-adult stage). The females are fertilized by the males and lay the eggs in the cup of the pines. At approximately 4 weeks the first caterpillars appear. Along its development, 4 moults have been described, from the L2 it is almost urticariform and the L3 is the one that forms a silk nest on the branch of the pines very easy to identify. They rarely abandon the pine where you find them, only shifting to other contiguous branches to feed, aided by a thread of silk they have been leaving behind as a reference for their displacement. Between February and July there is undoubtedly the final phase and the most important for pet owners, the caterpillar is already in the final phase and when the temperature oscillates 20oC appears the burial reflection and caterpillars, forming more or less rows long and in procession, they go in search of a suitable place for burial and effect the process of crystalization. This procession of caterpillars, has developed a coating of stinging hair to defend itself from predators, acting as real harpoons.

Abandoned nests also have urticating hairs so the wind can dislodge these hairs and put them in contact with skin and mucous originating reactions when the animals have not been in direct contact with the caterpillars.

The affected are usually dogs mainly and rarely cats. They are usually attracted by the rows of caterpillars and end up molesting her with snout and tongue mainly. Symptoms are of rapid onset and vary from milder form (swelling of lips, snout and tongues with a slight salivation) to more severe forms with very important swellings of mouth and tongue and as days progress they may necrose and partially detach. Pictures of vomiting, conjunctivitis, and keratitis may also present.

The prophylaxis is going to consist of preventing dogs from being around the pines during the processional season. Fumigations in late summer and early fall are very effective. Nest destruction is also interesting. 

The owner could initiate treatment by washing the affected area with pressurized tempered water while calling emergency service. It is very important not to rub the area to prevent the hairs from tangling.

As might be expected, poisonings by pine processional, suppose a situation of emergencies for the proprietor, without forgetting that his suffering would be possible even in seasons when the procession of the caterpillar does not occur.

IMAGES:

• Processionary larvae - [1]: Salvatore Ingala, CC BY-SA 3.0, via Wikimedia Commons
• Adult specimen of pine  processionary - [2]: © entomart
• Pine procession shifting in characteristic way - [3] : Jürgen Appel