The processionary caterpillar is a risk for the family and a real danger for your dog

Oruga procesionaria, un riesgo para la familia y un peligro real para tu perro

Pine processional caterpillar may cause mild skin reactions. In some allergic people, it may cause anaphylaxis. In the case of pets, the consequences are more serious since the caterpillar hairs act like poisoned darts that, in the worst case, could cause death by asphyxiation. It is precisely in the spring that we have to be more attentive to avoid undesirable accidents.

The processionary, Thaumetopoea pityocampa, is a caterpillar that you will undoubtedly know. It is found in parks, rural areas and forests where there are pines and cedars. It is called a processionary because when the lepidoptera break their pockets in which they nest, go down or fall to the ground to bury themselves, complete their metamorphosis and become a butterfly, forming a parade that slides like a procession. Currently, as stated by Dr. Cristina Villegas, head of Dermatology at the Hospital Universitario Sanitas La Moraleja, “the procession is a plague in the Mediterranean countries and is spreading northwards due to global warming”. What’s more, if it used to be a caterpillar typical of coastal and warm areas, today it is also invading the forests of the Pyrenees.

Where is the risk?

These caterpillars have very small urticating hairs that are easily detached from their bodies and are the cause of the adverse reaction that cause , even after death. Symptoms are usually instantaneous and generally remit within a few days. They consist of red welts, swelling and a lot of itching. They can also cause eye and bronchial problems and, in extreme cases, severe anaphylaxis in those suffering from allergy mediated by IgE antibodies.

The caterpillars usually walk on the ground in February, March and April (depending on the area in which it is located). For example, in the coldest, it can be delayed) therefore it is recommended to avoid the areas in which children and pets can be found and given attention , since they are the population groups most susceptible to touch, by accident, the caterpillar and suffer a reaction. It is also recommended not to put yourself under the nests, try to break them, or even touch the trees where they are, since the trunks could leave hair remains and produce urticariae. 

What should you do if it ‘stings’?

If we observe where they are, it is difficult for us to suffer their ‘bite’. However, because the hairs come off very easily, they could be suspended in areas such as pine picnic tables, for example. In any case, if you have contact with her this is what you should do, according to Dr. Cristina Villegas of Sanitas:

1. Remove the caterpillar if it is still in the body. Use tweezers, or gloves, but don’t do it with bare hands.
2. Place tape or tape over the site of the bite. Stick it on and remove it repeatedly.  This way we remove the thorns, hairs and toxins.
3. Wash the injured area with neutral soap and water, and remove contaminated clothing.
4. Oral antihistamines may be taken to reduce itching.
5. A corticosteroid cream, two or three times a day, will solve the problem.
6. If there is general affectation, with respiratory difficulty, go to an Emergency Department.

Why are they dangerous to pets?

The processionary is especially dangerous for pets as well as for livestock. When the caterpillar sniffs, it defends itself by throwing its hairs that act like poisoned darts and adhere to the most unprotected areas of the skin such as the mouth, tongue, nose or eyes. The problem is not only the pain and itching it produces, it can also necrosar (tissue death) the tongue and, if the infection reaches the larynx, cause death by suffocation.

To know if your pet has been in contact with a caterpillar, you must observe its behavior. “The animal that has been in contact with the caterpillar, due to the irritation produced by the contact with the hairs that it detaches, is nervous with constant swallowing, touches its mouth with its legs and hypersaliva . In a few minutes inflammation and necrosis of the tongue is seen and vomiting may occur if it is swallowed. It is also not very normal to swallow because of the irritation caused by the caterpillar’s hairs, as these cause it to be released once it has been sucked or bitten”, says Carlos Gómez, veterinarian at the Clínica Éboli, in Madrid.

It is very important that you act immediately and take your pet to a veterinary centre where they can be treated urgently. “If allowed to progress, they may suffer dyspnea (shortness of breath), laryngeal edema (inflammation), especially from ingestion, hyperthermia (increased temperature), convulsions, systemic inflammatory response, even disseminated intravascular coagulation and consequent death. Local lesions tend to progress to necrosis, with the possibility of tissue loss,” he warns.

What to do if it ‘itches’?:

In addition to taking you to the vet, immediacy will play in your favor. That’s why you can take these measures in the same place where he’s been bitten:

  • Wash him avoiding swallowing the hairs, that is, do it in such a way that they can be released towards the outside.
  • Do not rub
  • If possible, use physiological saline solution. In periods of greatest risk, you can carry it in your walking bag.
  • Take him to the vet in case he needs emergency treatment.
  • If you live in high-risk areas and far from a veterinary centre, consider having a medicine to stop the reaction in your first-aid kit.