Urticaria or Hives in Dogs
What is urticaria?
Urticaria or hives is a skin condition characterized by raised red skin welts. Urticaria is commonly caused by an allergic reaction. These swollen welts can appear anywhere on the body, including the face, lips, tongue, throat, and ears. The individual welts can vary in size from about 5 mm (1/4 inch) to several cm in diameter, and if there are a large number of them, they can coalesce or merge together. The hives are usually very itchy.
What causes urticaria?
Urticaria is generally caused by direct contact with an allergenic substance, or an immune response to food or some other allergen, but can also appear for other reasons, including vaccinations and medications.
Is urticaria dangerous?
If the urticaria is the result of insect stings, particularly bees, dogs can experience dramatic swelling around the face and lips. If the swelling progresses to the throat, breathing can be compromised resulting in a medical emergency called anaphylaxis (see fact sheet called Anaphylaxis). Most cases of urticaria are self-limiting and cause no significant health threat to your pet.
Can it be treated?
Yes. Antihistamines and corticosteroids by injection usually bring about a dramatic improvement, sometimes in as little as a few minutes.
If your dog develops a rash that goes away without treatment, it is important to report this incident to your veterinarian so that it can be noted in your dog's medical records. Dogs that have episodes of urticaria may have other allergic reactions or the episodes may worsen in the future.
If the episode was related to a vaccination, your veterinarian will modify future vaccination protocols or may pre-treat your dog with antihistamines to minimize this reaction.