There are a wide variety of potential causes for dog mouth blisters, including kidney disease, cancer, infection, and dental problems. All of these issues should be treated by a licensed veterinarian. Occasionally a dog may get mouth blisters from chewing on hard objects which may splinter and become lodged in the mouth or cut the dog's lip or gums. If this occurs, an infection may take root in the abrasion.
As part of a normal physical exam, dogs' mouths should be checked since oral health can be a good indicator of overall health. Although in many cases the causes of mouth blisters in dogs are benign and fully treatable, sometimes they are cause for concern. Oral cancer and kidney disease can both lead to mouth blisters. In many cases these will be the only noticeable physical symptom that owners detect.
Many times, dog mouth blisters will be caused by underlying dental problems. Gum disease and mouth infections may occur together since bacteria can enter infected gums. Dogs also sometimes chew on things they shouldn't. Pieces of bone, sticks, or other hard items can sometimes lodge in the gums or cheek and bacteria may enter the wound, causing an infection. If a bacterial infection is to blame for the mouth blisters, the area will likely also be inflamed and red.
More serious conditions may also lead to dog mouth blisters. The most serious of these is oral cancer, which often leads to blisters in the back of the mouth close to the throat. Kidney disease may also cause sores or ulcers to appear in the mouth once the condition becomes severe enough.
Owners who notice blisters in their dogs mouths should first try to alleviate any pain. This can be done through oral numbing medications or other painkillers that have been approved by a veterinarian. Dogs should be examined by a vet as soon as possible after the discovery of a mouth ulcer to ensure that it is not serious. Minor infections and sores will typically be treated with medication, while more serious conditions may require ongoing treatment.
Pet owners should not give their dogs any medication without first speaking to a vet. Dog mouth blisters that are accompanied by bleeding, oozing, or severe pain may require immediate medical attention at an emergency vet hospital. This also goes for dogs that have severe fever, vomiting, diarrhea, or loss of appetite. These could be signs of a serious infection or condition.