What To Do If Your Horse Goes Into Anaphylactic Shock?

Anaphylactic shock is an acute systemic allergic reaction that occurs when a substance called an antigen (foreign protein) is administered to an animal that has been previously exposed to the antigen and acquired a sensitivity to that antigen. Such a reaction occurs rapidly and may be seen following a drug injection, vaccination, insect bite, or the following ingestion of certain plants. It is actually a violent exaggerated response of the immune system and produces severe allergy-related signs such as vascular collapse, urticaria, and bronchospasm. A veterinarian should be contacted immediately if anaphylactic shock is suspected. If left untreated, anaphylactic shock can terminate in death in a matter of minutes.

Early treatment consists of prompt administration of epinephrine (adrenalin), which may be repeated at 15-20 minute intervals. Antihistamines are also given intravenously whenever the reaction is severe or not satisfactorily responsive to epinephrine. Later treatment includes fluids for vascular volume expansion, corticosteroids in large doses, and vasoactive and inotropic agents (i.e., those that increase the contractility of the heart.