Diseases That Cause Dogs to Foam at the Mouth

Just because a dog foams at the mouth does not necessarily mean he has rabies. Foaming, drooling and frothing at the mouth are rarely caused by rabies in dogs that have been vaccinated. Foaming can be an indication that the dog has a serious disease or condition, but can also be an indication of something as simple as anxiety, car sickness or an upset stomach. If the dog has persistent hypersalivation (foaming at the mouth) then he should see a veterinarian so the cause can be determined.

  1. Dental Disease

    • Dogs that have serious dental disease may experience severe foaming and drooling at the mouth. Canine dental problems are often manifested in periodontal disease, which causes inflammation and infection of the tissue surrounding the teeth. The infection causes the gums to recede, exposing tooth roots and causing the teeth to fall out. Veterinarians estimate that 2/3 of adult dogs suffer from periodontal disease.

    Kidney Disease

    • Kidney (renal) disease is the leading cause of death in older dogs. It is a disease that progresses slowly, and next to arthritis it is the most common illness in older dogs. Every dog is different and experiences different symptoms of renal disease. Among other symptoms, a dog with kidney problems can have a strong chemical odor to her breath, nausea and vomiting and a pale mucous membrane coming from her mouth. This may look like a foaming of the mouth, especially if the dog has other renal symptoms like mouth ulcers.

    Epilepsy

    • Dogs that suffer from epilepsy can experience a great deal of foaming at the mouth during seizures. When a grand mal seizure occurs, the dog's muscles begin to contract and he usually falls to the side with his legs stretched straight out and his head back. You may notice excessive drooling accompanied by urination and defecation, and then the dog will begin to jerk or make a type of running movement with his legs. After the seizure passes, the dog may lie motionless for a brief period and then get up and appear normal, although there may be lasting side effects like blindness or disorientation.