Hi
Sadly the encounter of dog and caterpillar can result in death for the dog

but if your lucky the dog may only loose part of its tongue!! When the caterpillars are disturbed they shoot off fine hairs which usually for a dog mean they get stuck in the nose, throat, eyes etc, because dogs are always using their noses to investigate stuff. For us humans they cause skin rashes and if inhaled they can cause much bigger problems. Even sitting under a tree with the nests (the nests are the white silky things you see in the pine trees) in can cause reactions, so the best bet is to stay clear of them. These caterpillars also kill the pine tree eventually
