Swelling can be categorized as localized or general. Depending on the type of swelling, there are different likely causes.
Causes of Localized Swelling:
Swelling in a particular area of your dog’s face (mouth, cheek, eye, etc.)
Trauma or Injury
Localized swelling on your dog’s face could be a sign of an injury. Just like humans when we bump our heads, swelling can occur as a result. Sometimes swelling associated with trauma or injury can be more severe, such as a broken bone. In these cases, your dog will likely show signs of pain.
Abscesses (a pocket of pus) often occur as a result of a bite wound or scratch that becomes infected. They appear as a swelling that may feel hard or squishy. Often accompanied by a fever, an abscess will make your dog feel very sick and is most often treated with drainage and antibiotics.
A tooth root abscess can appear as a swelling near your dog’s eye. A tooth root abscess occurs when the root of the tooth becomes infected, through dental disease or pulp exposure. As the swelling may occur just under the eye (if the affected tooth is an upper tooth), it may look like swelling of the eye, but often the real culprit lies below the gum line. Other dental problems such as a jaw fracture or oral tumour can cause swelling of the mouth.
A bug bite, such as a spider bite or a bee sting, will often cause localized swelling where the bite occurred. Bug bites often appear super dramatically! They may also cause overall swelling or puffiness, not just localized to one area.
General, overall swelling:
Overall swelling and puffiness of your dog’s face
Your dog’s face may puff up like a balloon if they’re having an allergic reaction. This often occurs as a response to environmental allergies such as particular grasses and pollens. Dogs can also be allergic to bug bites, chemicals, plants, food, fragrances, and other things. On rare occasions, dogs can also be allergic to some vaccines (just like humans).
In addition to a swollen face, your dog may experience hives, itchiness, and sneezing when they are having an allergic reaction (just like us!) You may notice your dog pawing at their face, or rubbing their face on the ground to try to relieve the itch.