Owners often ignore signs of anaphylaxis because they assume their dog is just showing signs of less serious allergies. But anaphylaxis is both faster-acting and more severe.
“Slower onset hypersensitivity reactions are more commonly seen causing hives and/or facial swelling around the head, lips, muzzle, and around the eyes. The swelling can sometimes be so severe that the dog cannot open its eyes. These types of reactions are often caused by allergic reactions to drugs or vaccines, chemicals, something eaten, or insect bites. They generally develop within 20 to 60 minutes of exposure to the allergen (antigen),” explains Dr. Klein. “Hives and swelling are usually not life-threatening and typically go away by themselves if the source of the allergic reaction is removed or passes through the body. Veterinarians treat these reactions by giving appropriate medications such as antihistamines and corticosteroids.”
Dog owners may also overlook signs of anaphylaxis because they look for respiratory signs, which are the main symptom in humans. But dogs are different.
“Dogs differ from other domestic animals in that the major organ affected by anaphylaxis is the liver rather than the lungs,” Dr. Klein explains. “Gastrointestinal signs are the major signs of an anaphylactic reaction rather than respiratory signs. These signs include sudden onset of diarrhea, excessive salivation, vomiting, and, in extreme cases, a drop in blood pressure (shock), seizures, coma, and death. The dog’s gums may be pale, and the limbs may feel cold. The heart rate is generally very fast, but the pulse is weak.”
