Over 15 years handling, testing, and restoring pocket, fixed-blade, and Damascus steel knives across hunting and everyday-carry disciplines.
Why are pine processionary caterpillars particularly dangerous for dogs? When is the procession season?
The pine processionary caterpillars are covered in thousands of microscopic stinging hairs.
These hairs release a highly irritating toxin that triggers a violent inflammatory reaction, sometimes within just a few minutes.
For dogs, the danger stems from their natural curiosity; they sniff the ground, lick things easily, and may even pick them up in their mouths while playing.
The area most frequently affected is the tongue, which carries a high risk of massive swelling, ulceration, and subsequent necrosis if treatment is delayed.
For the pine processionary, the most dangerous period generally corresponds to when the nests descend, between February and April, often peaking in March depending on the region and weather. In the south and warmer areas, this can start even earlier.
What are the main symptoms that should raise immediate alarm?
Signs often appear immediately or within 2 hours.
The most telling symptoms include:
- Sudden hypersalivation
- Severely swollen tongue or lips
- Dog rubbing its muzzle
- Agitation, intense pain
- Vomiting
- Difficulty closing the mouth
- Redness or abnormal discoloration of the tongue
- Respiratory distress in severe cases
- …
The most worrying sign is a tongue that swells rapidly and turns red, then purplish or black.
What should an owner do immediately if they suspect their dog has touched, licked, or inhaled caterpillar hairs?
You must act immediately, without waiting to “see if it goes away.”
Immediate best practices
- Move the dog away from the area
- Wear gloves
- Rinse the mouth, tongue, or affected area thoroughly with cold water
- Rinse with a gentle stream, without rubbing
- Consult a veterinarian or emergency service immediately
The goal of rinsing is to remove as many hairs as possible before they continue to release their toxin.
What actions or mistakes must be avoided at all costs?
Certain mistakes can significantly worsen the injuries.
What NOT to do
- Do not rub the tongue or muzzle
- Do not use a cloth or dry compress
- Do not try to remove the hairs with bare fingers
- Do not induce vomiting
- Do not wait for edema to appear
- Do not give human medication
Rubbing breaks the stinging hairs and releases even more toxin, which can worsen necrosis.
What prevention advice should be given during the high-risk season for processionary caterpillars?
Prevention relies primarily on vigilance during walks.
Simple tips to share with owners
- Avoid areas with infested pine, cedar, or oak trees
- Keep an eye out for silky white nests in the trees
- Keep your dog on a leash in wooded parks during spring
- Prevent sniffing at the base of pine trees
- Avoid windy walks near nests
- Notify the town hall or parks department if nests are visible
- Consult a vet quickly at the slightest doubt
We would like to warmly thank the Ric et Rac Veterinary Clinic, Dr. Marc Leclerc, for the time he dedicated, the quality of his answers, and his invaluable expertise, as well as Dr. Odin, who treated our dachshund Néo on the day of his admission, for his intervention and support.
The DoxieLife team – 💚
