The processionary caterpillar no longer waits for spring: risks and prevention

Thaumetopoea pityocampa, commonly known as the pine processionary caterpillar, is one of the most significant forest pests in the Mediterranean region and a growing threat to our companion animals. 

Climate change is profoundly altering its biological cycle. 

In the last decade: 

• In some areas of Spain, processionary caterpillars have shifted from appearing in April to being seen as early as January or February. This earlier emergence is due to rising temperatures and fewer episodes of severe cold, which accelerate larval development and increase activity.
• Mild winters allow caterpillars to remain active for longer periods, extending the risk season by several months.
• As a result, contact with people and pets has become more frequent in parks, gardens, and urban areas. 

Why is it a health risk?

The larvae are covered with urticating hairs called tricomes, which contain a toxin capable of causing severe reactions even without direct contact with the caterpillar itself. Exposure can occur simply through airborne hairs or those deposited on surfaces. 

In humans, exposure may cause: 

• Severe irritation of the skin, eyes, nose, and throat.
• Allergic reactions.
• Serious respiratory problems. 

In dogs, the risk is even greater: 

• Severe inflammation of the nose, lips, and muzzle.
• Vomiting and excessive salivation.
• Necrosis of the tongue or throat, which may develop rapidly.
• Acute pain and fever.
• Potentially life-threatening anaphylactic shock. 

First aid if your pet comes into contact 

These measures do not replace veterinary care, but they may help minimize damage while traveling to a veterinary clinic:

1. Do not rub the affected area. Rubbing releases more hairs and worsens the reaction, potentially embedding them deeper into the skin or mucous membranes.
2. Rinse with lukewarm water, without pressure or scrubbing. Keep the area under a gentle stream of lukewarm water to remove hairs without breaking them and to reduce exposure time.
3. Remove visible hairs without using bare hands. Use gloves or tweezers. Do not use towels or cotton, as they may break the urticating hairs.
4. Prevent the animal from licking the affected area. The tongue is one of the most commonly affected areas, and necrosis can develop within hours. Minimizing contact with the oral mucosa is essential.
5. Seek immediate veterinary attention. Early treatment can prevent serious complications. In cases of anaphylactic reaction, specific medication may be required. 

The pine processionary caterpillar is no longer a problem limited to spring. Global warming has advanced its appearance, and it now poses a real threat to animals and people even in the middle of winter. 

Understanding its effects, recognizing it promptly, and knowing how to respond can save a pet's life.