Mammalian bites: documentation that holds up

Most bite-wound liability hides in two places: the "fight bite" the patient won't admit to, and the prophylaxis decision (antibiotics, tetanus, rabies). The defensible chart documents the mechanism and the over-the-knuckle exam, the closure rationale, and each prophylaxis call.

01What's at stake

A wound over the knuckle (MCP joint) from striking a mouth is a clenched-fist injury until proven otherwise — teeth penetrate the joint/extensor tendon in up to two-thirds of these, then the tear seals and seeds a deep infection. Cat punctures look trivial but infect at roughly double the rate of dog bites. And the rabies decision — especially bat exposure — can't be deferred.

02Can't-miss / high-stakes

• Fight bite (clenched-fist, over the MCP) — joint/extensor-tendon/deep-space involvement; Eikenella.
• Deep hand-space infection, septic arthritis, osteomyelitis — especially delayed presentation.
• Cat-bite puncture — deep inoculation, Pasteurella, rapid infection.
• Retained tooth / foreign body; pediatric dog-bite head wounds (skull/dura).
• Rabies exposure (bats, wildlife, unprovoked) and human-bite bloodborne exposure (HBV/HIV).

03History & exam

• Hand wound from an altercation? → assume fight bite — examine over full flexion AND extension in a bloodless field.
• Cat or puncture wound, or delayed presentation (>8–24h)? → high infection risk
• Immunocompromised/asplenic/diabetic? → prophylaxis + Capnocytophaga risk
• Animal type, provoked vs unprovoked, vaccination/quarantine status, geography? → rabies decision
• Missing teeth of the biter, or wound over a joint? → x-ray for tooth/air/fracture

04Management

• Irrigate (high-pressure, saline or tap water) and explore; open and clean cat punctures; debride devitalized tissue; x-ray for tooth/air/fracture.
• Closure: dog bites may be closed (esp. face) — but not hand bites, punctures, or infected/delayed wounds; cat and human punctures are not closed; fight bites are left open with hand-surgery involvement.
• Antibiotics: amoxicillin-clavulanate first-line; prophylaxis for cat bites, punctures, hand bites, human bites breaching dermis, immunocompromise, and delayed presentation. Superficial non-hand human bites generally don't need antibiotics.
• Tetanus if >5 years or unknown (± TIG if series incomplete).
• Rabies: assess animal type/behavior/geography; observe a healthy dog/cat/ferret 10 days; PEP (vaccine ± HRIG) for wildlife/bat exposures unless excluded; previously vaccinated get a 2-dose vaccine and no HRIG.

05What to document

06Where charts fail

• Closing a knuckle wound without recognizing/exploring a fight bite.
• Treating a cat puncture as trivial (no antibiotics, primary closure).
• Closing puncture wounds or infected/delayed wounds.
• Missing the bat/wildlife rabies decision, or giving HRIG to a previously-vaccinated patient.
• Not documenting tetanus status, the antibiotic decision, or the 24–48h wound recheck.

07Sources

• Edens MA, Michel JA, Jones N. Mammalian bites in the emergency department: recommendations for wound closure, antibiotics, and postexposure prophylaxis. Emergency Medicine Practice (EB Medicine). 2016;18(4).
• Talan DA, Citron DM, Abrahamian FM, et al. Bacteriologic analysis of infected dog and cat bites. N Engl J Med. 1999;340(2):85-92.
• Cheng HT, Hsu YC, Wu CI. Does primary closure for dog bite wounds increase the incidence of wound infection? A meta-analysis. J Plast Reconstr Aesthet Surg. 2014;67(10):1448-1450.
• Manning SE, Rupprecht CE, Fishbein D, et al. Human rabies prevention — United States, 2008: ACIP recommendations. MMWR Recomm Rep. 2008;57(RR-3):1-28.

© 2026 Kim Trinh, MD. All rights reserved. Educational only — synthesized from EB Medicine and primary literature. Synthetic examples. Not medical advice — apply local protocol and judgment.