Veterinary Anaphylaxis Treatment Dose Calculator
Weight-based emergency drug doses for canine and feline anaphylaxis - epinephrine, antihistamine, steroid, H2 blocker, IV fluids.
Species
Patient weight (kg)
Frequently asked questions
Why is epinephrine the first-line treatment, not diphenhydramine?
Diphenhydramine only blocks H1 receptors - it does nothing for the bronchoconstriction, vasodilation or hypotension that kill in true anaphylaxis. Epinephrine reverses all three immediately. Antihistamines are adjunctive only.
IM or IV epinephrine for anaphylaxis?
IM into the thigh is preferred for first dose - faster, more reliable absorption than SC, less arrhythmia risk than IV. Save IV for patients with cardiac arrest or no IM response after 5 minutes.
Do I need to admit anaphylaxis patients overnight?
Biphasic reactions occur in roughly 5-10% of cases, typically within 8-12 hours. Patients who needed > 1 epinephrine dose, had prolonged hypotension, or have respiratory involvement should be observed at least 8-12 hours. Mild reactions can often be discharged after 4-6 hours of stable monitoring.