Vet Approved Guide: Canine Anaphylaxis – Signs, Treatment & Urgent Care in 2025 🚨🐶

By Dr. Duncan Houston BVSc

Anaphylaxis is a sudden, life-threatening allergic reaction that affects multiple body systems at once. It can occur within minutes after exposure to triggers like insect stings, medications, vaccines, or foods. Treatments like epinephrine and IV fluids must be administered immediately—this guide helps you act fast. 🛡️

⚠️ What Is Anaphylaxis?

A severe, systemic hypersensitivity reaction (Type I IgE-mediated), releasing histamine and other inflammatory mediators from mast cells and basophils—impacting cardiovascular, respiratory, gastrointestinal, and skin systems.

🧪 Common Triggers

• Insect stings or bites (bees, wasps, ants) — nearly 50% of cases
• Medications (antibiotics, NSAIDs), vaccines, or blood products
• Foods, chemicals, environmental exposures (late onset)

🚨 Red Flag Symptoms

Symptoms typically appear within minutes to 30 minutes of exposure. A life-threatening emergency requires prompt veterinary care.

• Gastrointestinal distress: Vomiting, diarrhea (sometimes bloody), drooling—most common in dogs
• Cardiovascular collapse: Pale gums, weak/rapid pulse, low blood pressure, collapse, shock, seizures
• Skin & facial swelling: Hives, angioedema, itchy red welts—usually early signs
• Respiratory distress: Labored breathing, wheezing, possibly stridor or cyanosis
• Nervous signs: Weakness, tremors, incontinence, confusion, collapse

🩺 How Vets Diagnose It

• Immediate physical exam and history of exposure
• Lab results: liver enzymes, hemoconcentration; ultrasound may show gallbladder edema
• Diagnosis based on rapid onset and involvement of ≥2 body systems

⛑ Emergency Treatment Steps

• Epinephrine: 0.01 mg/kg IM (1:1000); IV infusion in shock cases
• IV fluids: Restore blood pressure and combat shock
• Oxygen/airway support: Intubation if airway swelling is present 
• Antihistamines: Diphenhydramine ± ranitidine to reduce histamine effects
• Corticosteroids: Dexamethasone to reduce inflammation and prevent rebound reactions
• Frequent monitoring: Vitals, ECG, temperature—to check for biphasic or persistent reactions

👩⚕️ Prognosis & Follow-Up

• Survival with upfront care is high—~85% for severe cases
• Mild reactions may be outpatient-treated; severe cases require hospitalization 2–3 days
• Dogs may experience worse reactions upon repeat exposure—consider allergy testing and immunotherapy

🛡 Prevention Tips

• Avoid known triggers (insect control, careful medication handling)
• Monitor closely after new vaccine or drug administration
• Consider carrying an emergency plan or an injectable epinephrine kit—ask your vet 

📱 Vet-Approved Support Tools

• Ask A Vet: 24/7 emergency guidance during suspected episodes. 🩺

🎯 Final Thoughts

Anaphylaxis is rare but can strike any time, especially after insect bites, medications, or vaccines. Fast recognition and emergency treatment—especially with epinephrine—can be lifesaving. After recovery, plan to avoid repeat exposure and talk to your vet about long-term prevention. 🐾

For immediate help and peace of mind, download the Ask A Vet app now. 📲🐶