Rationale:

• Dog bites are less likely to become infected than either cat or human bites.
• Unprovoked animal bites carry a higher risk of rabies transmission than similar bites from provoked animals.
• Animals with an up-to-date rabies vaccination are unlikely to transmit rabies.
• Bite wounds in patients presenting more than 24 hours after injury carry an increased risk of infection.
• Large dogs carry a high risk of crush injuries to deep structures.

Evidence:

• Various review articles have reported that 28% to 80% of cat bites become infected, whereas only 2% to 20% of dog bites lead to infection (3; 4; 19; 20).
• Human bites appear to carry a high risk of infection (up to 50%), although there is selection bias, given that only 3.6% to 23% of human bite wounds are seen by a physician, according to one review article (4).
• A case series of 434 consecutive human bite wounds at an institution for developmentally delayed residents revealed an infection rate of 17.7% (21).
• Large dogs can generate up to 450 psi of force, which can cause severe damage to vital organs and vascular structures (5; 20).

Comments:

• None.