🗂️ Dog Bite – Rapid Flowchart
1️⃣ Assess & History – 👀 ABCs + Analgesia; 📝 History: timing, animal, tetanus, rabies risk, comorbidities 2️⃣ Irrigation – 💦 Copious irrigation & debridement (≥250–500 mL saline, high pressure) 3️⃣ Closure Decision – ✂️ Leave open: hand, puncture, crush, delayed >12–24 h, immunocompromised; 🙂 Primary closure: face/scalp, <12 h, well-vascularised; ⏳ Delayed closure 48–72 h if intermediate 4️⃣ Antibiotics – 💊 First-line: Co-amoxiclav; 🚫 Avoid fluclox/erythro/clinda alone; 🔄 Alternatives: Doxy+Met or TMP-SMX+Met 5️⃣ Tetanus – 💉 Booster if >5 yrs (dirty wound) or >10 yrs (clean wound); ⚠️ TIG if incomplete/unknown 6️⃣ Rabies – 🦠 Negligible in UK from vaccinated pets; ✈️ Travel/unknown animal: start PEP (vaccine ± HRIG) → discuss with ID/public health 7️⃣ Follow-up – 📅 Re-examine in 24–48 h (earlier for hand/face); ⚠️ Return if fever, spreading cellulitis, pain, loss of function

🗂️ Dog Bite – Rapid Flowchart

1️⃣ Assess & History – 👀 ABCs + Analgesia; 📝 History: timing, animal, tetanus, rabies risk, comorbidities
2️⃣ Irrigation – 💦 Copious irrigation & debridement (≥250–500 mL saline, high pressure)
3️⃣ Closure Decision – ✂️ Leave open: hand, puncture, crush, delayed >12–24 h, immunocompromised; 🙂 Primary closure: face/scalp, <12 h, well-vascularised; ⏳ Delayed closure 48–72 h if intermediate
4️⃣ Antibiotics – 💊 First-line: Co-amoxiclav; 🚫 Avoid fluclox/erythro/clinda alone; 🔄 Alternatives: Doxy+Met or TMP-SMX+Met
5️⃣ Tetanus – 💉 Booster if >5 yrs (dirty wound) or >10 yrs (clean wound); ⚠️ TIG if incomplete/unknown
6️⃣ Rabies – 🦠 Negligible in UK from vaccinated pets; ✈️ Travel/unknown animal: start PEP (vaccine ± HRIG) → discuss with ID/public health
7️⃣ Follow-up – 📅 Re-examine in 24–48 h (earlier for hand/face); ⚠️ Return if fever, spreading cellulitis, pain, loss of function

📚 About Dog Bite Risks

Polymicrobial flora: Pasteurella, Capnocytophaga, anaerobes, staph/strep.
High infection risk: hand, puncture/crush, near joints/prostheses, venous/lymphatic compromise, delayed presentation, diabetes, immunosuppression, asplenia, liver disease.
⚠️ Capnocytophaga canimorsus → fulminant sepsis in asplenic/cirrhotic patients even from minor bites.

🔍 Clinical Assessment

Explore under anaesthesia if needed; check ROM, distal sensation, cap refill.
Red flags: spreading cellulitis, pain out of proportion, crepitus, systemic toxicity, tendon/joint/bone involvement, immunocompromised host.

🧪 Investigations

X-ray: suspected fracture, foreign body, retained tooth, hand/joint involvement.
Bloods: FBC, CRP, U&E, glucose if systemic/unwell.
Swab/culture: only if clinically infected or failing therapy.

🩹 Wound Management

Irrigation: high-pressure saline (e.g. 35-mL syringe + 18G catheter).
Closure:
- 👐 Leave open: hand, puncture, crush, >12–24 h old, immunocompromised.
- 🙂 Primary closure: face/scalp (<12 h, well-vascularised) after thorough washout.
- ⌛ Delayed primary closure (48–72 h) if intermediate risk.
Immobilise & elevate wounds near joints/hand.

💊 Antibiotics (must cover Pasteurella + anaerobes)

Scenario	First-line	Alternatives (PCN allergy)	Duration
Prophylaxis (high-risk: hand, face, near joint, prosthesis, immunocompromised, delayed presentation)	Co-amoxiclav PO	Doxycycline + Metronidazole (adult); or TMP-SMX + Metronidazole	3–5 days
Infection (cellulitis)	Co-amoxiclav PO	Doxycycline + Metronidazole; TMP-SMX + Metronidazole	5–7 days
Severe/systemic/hand deep space	IV Co-amoxiclav or IV Piperacillin-Tazobactam	IV Ceftriaxone + Metronidazole (if not true anaphylaxis); Fluoroquinolone + Metronidazole (adults)	7–14 days (tailor to source control)

Notes: Flucloxacillin, erythromycin, and clindamycin alone are inadequate (no Pasteurella cover). Avoid doxy/fluoroquinolones in pregnancy & young children – seek specialist advice.

💉 Tetanus

Bites = tetanus-prone. Booster if >5 years since last dose (dirty wound) or >10 years (clean wound).
Give TIG if immunisation incomplete/unknown and wound tetanus-prone.

🦠 Rabies

Negligible in UK from vaccinated domestic dogs. ⚠️ Consider after travel/unknown animal in endemic areas.
PEP (naïve): vaccine days 0,3,7,14 (+ day 28 if immunocompromised) + HRIG infiltrated around wound for category III exposures.
Discuss with infectious diseases/public health; act promptly.

📅 Follow-up & Safety-net

Re-examine in 24–48 h (earlier for hand/face/high-risk). Mark cellulitis margins.
Escalate for spreading erythema, fever, severe pain, loss of function, systemic toxicity.
Hand bites: plastics/orthopaedics review for tendon sheath/joint involvement.

🏥 Admission / Senior Review

Systemic sepsis, rapidly spreading infection, deep space/osteomyelitis risk.
Involvement of bone, joint, tendon, or nerve.
Immunocompromised, asplenic, cirrhotic patients.
Facial wounds needing complex repair.
Concerns about home support or safeguarding.

📝 Documentation & Medico-legal

Photographs, wound size, neurovascular exam, washout volume, closure decision.
Record tetanus/rabies risk, antibiotics given, and rationale.
Safeguarding: children/vulnerable adults → consider abuse; report to public health/animal control as appropriate.

Cases — Dog Bite

Case 1: A 7-year-old boy is brought to A&E after being bitten on the right hand by a neighbour’s dog. There is a deep puncture wound between the thumb and index finger with surrounding erythema. His tetanus immunisation is up to date, but the dog’s vaccination history is unknown. Parents are anxious about infection and rabies risk.
Case 2: A 58-year-old man presents with fever, rigors, and spreading cellulitis 24 hours after being bitten on the leg by his own dog. He is diabetic and on long-term steroids for COPD. Examination shows erythematous, warm tissue with lymphangitis up the thigh. He is hypotensive and tachycardic on arrival.

Teaching Commentary 🧑‍⚕️

Dog bites are deceptively high-risk because their teeth cause crush and puncture wounds, seeding bacteria deep into tissues. The most common pathogens include Pasteurella multocida, anaerobes, and skin flora such as Staph. aureus. In Case 1, the key issues are wound cleaning, tetanus cover, rabies consideration (rare in UK unless bite abroad), and prophylactic co-amoxiclav. In Case 2, host factors (diabetes, steroids) predispose to fulminant infection and even sepsis. Urgent IV antibiotics, sepsis resuscitation, and surgical input for possible debridement are vital. Always consider both the injury mechanism and the patient’s background risk when managing bites.

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Dog Bites