It could be an allergic reaction.
Foaming at the mouth is not normal in any animal ! Get it to a vet - NOW !
Laziness, bloating, and mouth foaming
Probably not. I know when dogs ingest frogs it can make them very sick. If your dog for any reason starts foaming at the mouth, you should take it to a vet right away. Some frogs are poisonous and can cause this reaction.
No. If you are foaming, see your doctor.
When someone or something is foaming at the mouth, it is usually a sign of rabies. They should be taken to a doctor.
Dog has rabies/
When it's not foaming at the mouth
Rabies
No, foaming out of the mouth are signs of a bacterial infection.
Foaming at the mouth is NOT an actual sign of rabies. Most likely scenario is that the wolf that is foaming at the mouth has just run very fast or very far, causing it to salivate.
Foaming at the mouth (or some other aperture).