Facial Swelling in Cats and Dogs

Acute facial swelling in dogs can be a sign of an anaphylactic (allergic) reaction. This can often be accompanied by hives or an irregular haircoat and is obviously easier to see in dogs with short coats but can happen in any breed. Allergic reactions like this can occur up to twelve hours following vaccine administration, particularly if the dog has been exposed to that particular vaccine in the past. More commonly, however, these types of allergic reaction are due to some type of insect bite, even in the winter months. There are no simple tests to determine the cause of the reaction and usually treatment entails injections of steroids and antihistamines and requires emergency care. Generally, dogs do not experience life-threatening anaphylactic reactions to food, as people do. Facial swelling can become very severe, and rarely can include swelling of the pharyngeal (throat) tissues resulting in respiratory distress. In severe cases, some dogs go home on oral steroids and antihistamines and can sometimes require admission to the hospital for IV fluid therapy. Repeat exposure to the offending antigen can result in severe anaphylactic reactions, often preceded by vomiting, collapse, and a rapid heartbeat. If you are ever concerned that your pet is experiencing an allergic reaction, it is safest to have him or her evaluated by a veterinarian on an emergency basis.

Sometimes facial swelling is not related to allergic reactions. In cats, facial swelling is seen after acetaminophen (Tylenol) ingestion. Acetaminophen is very toxic to cats and they are sometimes inadvertently given this medication by well-intentioned owners (which is why is it always safest to consult a veterinarian and not give medications from your medicine cabinet to your pet) but some cats accidentally ingest pills that fall on the floor. Acetaminophen can cause facial swelling as well as swelling of paws and a dark, brown/blue color to the mucous membranes (especially the gums) but can be fatal if liver failure and/or anemia result. Any potential for acetaminophen ingestion in cats is grounds for a trip to the emergency room.

Facial swelling can also be a result of wounds. If your pet was in an altercation, swelling of tissues under the skin (cellulitus) or even abscess formation (collection of infection/pus under the skin) can cause facial swelling. In relatively rare cases, dogs with enlarged lymph nodes due to cancer, inflammation, or infection can develop facial swelling. These diagnoses all require medical attention, so if your pet’s face ever seems swollen, the best option is to have your pet seen by your primary veterinarian or an emergency veterinarian as soon as possible.