Dogs foaming at the mouth can have many reasons. Where dogs are regularly vaccinated against rabies, it is usually not the cause. Of course if you are not sure about vaccinations, rabies can’t be ruled out.
If you suspect your dog might be poisoned, this is an emergency situation and your dog should be seen by a veterinarian as soon as possible.
Dogs like humans can sometimes feel nauseous for no apparent reason and excess saliva can appear as foam around the mouth area.
If your dog has a seizure, it is not unusual to have foaming at the mouth.
Infections such as kennel cough, tonsilitis, abcesses, tumors, injuries can also cause a dog to salivate excessively, producing foam.
Excitement or stress can produce panting and drool that appears as foam at the mouth.
Bloat (stomach torsion) can also cause excessive panting and drooling with foaming at the mouth. Bloat can be a life-threatening situation and your dog should be seen by a veterinarian as soon as possible.
Difficulty breathing or swallowing with foam buildup at the mouth is an emergency and your dog should be seen by a vet immediately.
If your dog has exercised vigorously and you see foam around the mouth area, it should disappear when the dog stops activity.
Unless exercise is the cause of foaming at the mouth, in all other instances, it’s important to get your dog to a vet as soon as possible to determine the underlying cause of foaming at the mouth.