Some species of toads secrete a toxic substance on their skin. This passes into the mouth of any dog that picks up the toad to play with it. Certain types of longhaired caterpillar can also produce similar irritants.

Treating Poisoning

itchiness, redness, and swelling can be reduced by bathing the mouth with cold water. A water spray is ideal for flushing out the mouth but do not let the dog swallow any water.

Contact  a vet if the dog swallow any water. Contact a vet if the dog is in discomfort; it may need antihistaminics to reduce swelling.