Cat bites
- Microbiology & Risk:
- Pasteurella multocida (most common, >75%) + oral anaerobes.
- High infection rate (>50%) due to deep, narrow puncture wounds inoculating periosteum or joint spaces.
- Clinical Findings:
- Rapidly progressive erythema, pain, and swelling (<24 hrs).
- Assess for flexor tenosynovitis (Kanavel signs: flexed finger, fusiform swelling, tendon sheath tenderness, pain on passive extension).
- Diagnostics:
- Clinical exam; get X-ray to R/O retained foreign bodies (cat teeth) or subcutaneous gas.
- Wound culture only if actively infected (purulence, erythema).
- Management:
- Wound Care: Copious irrigation; do NOT primary close (leave open).
- Abx Prophylaxis/Rx: Amoxicillin-clavulanate (Augmentin) first-line for all cat bites. c
- Penicillin-allergic: Clindamycin + (Fluoroquinolone or TMP-SMX). Avoid macrolides or 1st-gen cephalosporins (poor Pasteurella coverage).
- Adjuvants: Tdap booster (if >5 years since last dose) +/- Rabies PEP (if wild cat).
- Surgical I&D: Urgent consult for IV Abx + debridement if deep space infection (e.g., tenosynovitis, septic arthritis).
- Complications: Rapid-onset osteomyelitis, septic arthritis, and tendon rupture.
Dog bites
- Key Microbiology:
- Pasteurella multocida: Most common, rapid onset (<24 hr).
- Capnocytophaga canimorsus: Severe sepsis/DIC/purpura fulminans in asplenic or cirrhotic pts.
- Staph / Strep / Anaerobes: Polymicrobial coverage required.
- Initial Management:
- First Step: High-pressure profuse saline irrigation + debridement.
- Closure:
- Leave open (secondary intention): Deep punctures, hands/feet, crush wounds, presentation >24 hr.
- Primary closure: Uncomplicated facial wounds <12-24 hr only.
- Antibiotic Prophylaxis:
- Indications: Hand/foot wounds, deep punctures, crush injury, immunocompromised, active infection.
- 1st-line: Amoxicillin-clavulanate (Augmentin) PO x 3-5 days.
- PCN Allergy: Clindamycin + (Ciprofloxacin OR TMP-SMX OR Doxycycline).
- Avoid: 1st gen cephalosporins & macrolides (poor Pasteurella activity).
- Tetanus Prophylaxis:
- Dirty/Puncture + ≥3 prior doses: Give Tdap if last dose >5 yr ago.
- Dirty/Puncture + <3 doses or unknown: Give Tdap + TIG.
- Rabies Post-Exposure Prophylaxis (PEP):
- Available/Healthy Dog: Observe dog x 10 days (do NOT start PEP immediately).
- If dog shows signs of rabies -> Euthanize, test brain, and start PEP immediately.
- Escaped, Stray, or Rabid Dog: Immediate RIG + 4-dose Rabies Vaccine (Days 0, 3, 7, 14).