Facial Swelling in Dogs

Facial Swelling in Dogs
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Facial swelling in dogs can occur for a variety of reasons. In general, a swollen face is secondary to another problem. The cause of facial swelling may or may not be serious. However, it almost always requires medical intervention. Most commonly, acute (sudden) facial swelling in dogs occurs as a result of an allergic reaction. Facial swelling that develops more slowly may be in the result of a facial growth or tumor.

Causes of Facial Swelling in Dogs

There are many possible reasons why your dog has a swollen face. Because facial swelling is a sign of an underlying problem, these dogs will often show other signs of illness, such as lethargy and loss of appetite.

Allergic Reaction

When a dog's face suddenly becomes swollen, it is usually caused by an allergic reaction. Allergic reactions may be caused by bug bites, bee stings, vaccinations, medications, certain foods, toxin exposure, pollen, and other environmental allergens.

Allergic reactions cause an inflammatory response in the body. This can lead to hives and swelling, especially on the face. You may especially notice swelling of the muzzle and eyelids. The neck may be swollen as well and even affect breathing. Some allergic reactions will get worse quickly, leading to serious problems breathing or even seizures. Mild reactions tend to improve with little intervention, but major reactions are considered emergency situations.

Dental Issues

Facial swelling may be related to a problem with the teeth or mouth. Tooth abscesses and other dental infections can go deep beneath the gums and cause a pocket to fill with pus. This usually causes a dog's face to become swollen, especially beneath the eye. Broken teeth, oral injuries, and periodontal disease may also make a dog's face swell.


An injury to the face, head, or skin can lead to facial swelling. Common injuries like animal bites and other wounds can lead to infections that cause swelling. Snake bites often cause swelling of the face and neck, even if the bite is located elsewhere on the body.


Abnormal growths can occur on the face and head. Sometimes cancerous, tumors can cause pain and pressure buildup. Whether they are benign or malignant, facial tumors may spread and grow, causing damage to the facial nerves, muscles, and bones. Cysts are fluid-filled growths that are often benign. However, they can become quite large and visible, especially on the face.

facial swelling in dogs illustration
Illustration: The Spruce / Hilary Allison

Treatment of Facial Swelling in Dogs

The proper treatment of facial swelling in dogs usually depends on the cause. Before proceeding with treatment, it's important to contact your vet for advice.

Extreme allergic reactions and major infections may cause the airway to become swollen, obstructing breathing. This is an emergency situation; get to the nearest open veterinarian immediately.

Mild to moderate allergic reactions may be treatable at home using medication. A reaction is considered mild to moderate if your dog is breathing normally and acting relatively normal (no more than slightly lethargic). In these cases, your vet may recommend giving an over-the-counter antihistamine. If your dog's face is swollen for some other reason (or unknown reasons), the next step is to bring your dog to the vet for an exam. Your vet will recommend treatment based on the diagnosis.

Facial swelling due to dental or oral problems may require professional dental work. The dog is often treated first with antibiotics and anti-inflammatory medications before coming in for anesthesia and a full dental cleaning and examination. Dental x-rays may be done while your dog is under anesthesia. Depending on the cause, the vet may need to extract teeth or perform another kind of oral surgery. Your dog may be sent home with antibiotics to treat or prevent infection.

If trauma has occurred to the face or head, treatment depends on the severity of the injury. X-rays may be necessary to determine the severity. Begin by providing any first aid that is necessary, then get to the vet right away. Treatment often involves antibiotics, anti-inflammatory drugs, and supportive care. Serious injuries may require surgery. Snake bites are treated with supportive care and sometimes antivenin (if available and deemed necessary).

If your vet suspects a tumor and/or cancer, further testing will be needed to learn more. Your vet may recommend blood tests, x-rays, and testing of the tumor itself (usually a fine needle aspirate or biopsy is sent to a pathologist for microscopic analysis). Treatment depends on the diagnosis. Cancer may need to be treated with chemotherapy, radiation, and/or surgery.

How to Prevent Facial Swelling in Dogs

If you know your dog has allergies, try to minimize exposure to allergens. If approved by your vet, use antihistamines as prevention. If your dog is known to have vaccine reactions, make sure your vet knows so your dog can be treated in advance, minimizing the reaction. If you see that your dog has been bitten by a bug, stung by a bee, or otherwise exposed to an allergen, treat right away with an antihistamine (ask your vet for advice on this).

You can easily prevent most dental issues by taking good care of your dog's teeth. Begin a dental care routine for your dog and stick to it. Your dog will be much less likely to develop a dental problem and you will be more likely to catch issues early on.

Trauma cannot always be prevented, but you can take steps to keep your dog safe in general. Do not let your dog roam free or play off-leash in non-fenced areas. Supervise interactions with other animals so you can prevent fights. Bring your dog to the vet right away if any kind of trauma occurs.

Tumors and cancer cannot really be prevented. However, early action can minimize the damage done. If you notice your dog has a swollen face, it's important to act right away.

Article Sources
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  1. Allergies in Dogs. Merck Veterinary Manual

  2. Dental Disorders of Dogs. Merck Veterinary Manual

  3. Tumors of the Skin in Dogs. Merck Veterinary Manual