Bites, Animal and Human



Animal bite rates vary by species: dogs (60–90%), cats (5–20%), rodents (2–3%), humans (2–3%), and (rarely) other animals, including snakes.


All ages, but children > adults


  • 3 to 6 million animal bites per year in the United States; account for 1% of all injury-related ED visits
  • 1–2% will require hospital admission, and 20 to 35 victims die from dog bite complications, annually.

Etiology and Pathophysiology

  • Dog bites are more common than cat bites; most dog bites are from a known domestic pet; ~90% of cat bites are provoked.
  • Human bite wounds are typically incurred by striking another in the mouth with a clenched fist; human bites also occur incidentally (e.g., paronychia, thumb-sucking, or bites to the face, breasts, or genital areas).
  • Animal bites can cause tears, punctures, scratches, avulsions, or crush injuries.
  • Contamination by oral flora leads to infection.

Risk Factors

  • Clenched-fist human bites are frequently associated with the use of alcohol or drugs.
  • Patients presenting >8 hours following the bite are at greater risk for infection.

General Prevention

  • Instruct about animal hazards.
  • Educate pet owners.

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