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.
  • System(s) affected: potentially any

Pediatric Considerations
Young children are more likely to sustain bites and have bites that include the face, upper extremity, or trunk.


  • All ages, but children > adults
  • Dog bites: male > female patients; cat bites: female > male patients


  • 3 to 6 million animal bites per year in the United States (1)
  • 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 far more common than cat bites; most dog bites are from a domestic pet known to the victim.
  • Most (~90%) 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 due to nail biting; thumb sucking; or nonmalicious 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.
  • Cat bites are more often puncture-type wound.

Risk Factors

  • Older and/or male dogs are more likely to bite.
  • 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 of infection.

General Prevention

  • Instruct children and adults about animal hazards.
  • Enforce animal control laws.
  • Educate pet owners.

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