Hives (urticaria) and a swollen face (angioedema) are commonly the result of an allergic reaction. Small bumps will appear all over the dog’s skin and often the hair will be standing up over the swelling areas. When the body is exposed to one of the many allergens out there, the immune system reacts, or in most cases overreacts, and causes a hypersensitive state.
Hives can be itchy, so you may notice your dog scratching at the hives or rubbing its face. This is not usually a life-threatening situation, but you should seek veterinarian care as soon as possible. If you are not near a hospital, you can give your dog some diphenhydramine to combat the swelling until you can seek veterinary care. If you need to do this, call a veterinarian and ask for the correct dose.
Signs & Symptoms of Hives
- Medium to large areas of redness and swelling on the face, abdomen, and legs.
- Swelling around the muzzle
- Swelling around the eyes – it is not uncommon for the eyes to swell closed
- Excessive scratching of the hives
- Drooling if the muzzle starts to swell
Causes of Hives
If your dog breaks out with hives, they will do so about 20 minutes following an exposure to a substance that they are allergic to. The most common causes for hives or swelling of the face associated with an allergy are the following:
- Insect stings or bites
- Drug allergies – primarily following an injection of a drug
- Vaccine reaction – primarily following an injection of a vaccine
- Food allergies
- Chemical reaction – primarily insecticides
Treatment for Hives
Hives and swelling of the face is generally treated with the appropriate dose of antihistamines. It is not uncommon for the hives to resolve on their own once the allergen has moved through the body.