That is NOT 'normal' behaviour - seek professional advice from a vet NOW !
his breath stinks
They breathe through their nose and sometimes their mouth.
Foaming at the mouth is not normal in any animal ! Get it to a vet - NOW !
Perhaps he was getting a drink.
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).