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Wound infection is the greatest potential complication of bites.
Pasteurella species are common in dog and cat bite wound infections.
Eikenella corrodens is a common pathogen in human bite wounds.
Rabies and tetanus prophylaxis should be considered in all animal bite wounds.
Cat scratch disease due to Bartonella henselae may develop 7–12 days after a cat bite or scratch.
Bites wounds that are treated on an outpatient basis should be reevaluated in 48 hours.
Due to the risk of infection, tissue adhesives should not be used for wound closure.
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Mammalian bites are a common injury in the United States. According to the Centers for Disease Control and Prevention, there are 4.7 million people bitten each year with 800,000 seeking medical care, and approximately half are children.1 It is estimated that direct healthcare cost are as high as $165 million a year.2 The majority of bites are caused by dogs (80–90%), followed by cats (5–10%), humans (2–3%), and the remainder by other domesticated or wild animals.3 There are 10–20 fatal cases annually that mainly involve young children and infants.3
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Clinical Presentation
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Domesticated house dogs may exert a force of 200–400 pounds per square inch and police and fighting dogs up to 2000 pounds per square inch,4 enough force to penetrate sheet metal.5 Most bites are superficial crush injuries that cause ecchymoses and hematomas, without skin penetration,5 but may also cause lacerations, puncture wounds, severe crush injuries, tissue avulsions, fractures, dislocations, and neurovascular injuries.4 The upper and lower extremities are the most common site of injury for older children.3 Children less than 5 years old are commonly bitten on the head and neck due to their face-to-face contact with the offending dog.3,7 Most of the head and neck injuries involve the nose, lips, and cheeks.3,5 On rare occasions, especially in children less than 2 years of age, the bite may penetrate the cranium and lead to depressed skull fractures, intracranial lesions, and meningitis.3,5 Infection rates are generally low for dog bites. However, the site of injury plays a major role. Dog bites to the face have a lower risk of infection (1–5%), in contrast bites to the hands have a high infection rate (12–30%).5
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Cat bites are common in the upper extremities, mainly presenting with a puncture wound rather than a laceration or contusion.3 The feline characteristic long sharp teeth introduces bacteria into deeper tissues and may involve tendons, bones, or joints.5 This causes a wound that may appear small and unremarkable but have an infection rate as high as 80%.6 Cat scratch disease due to Bartonella henselae may develop 7–12 days after a cat bite or scratch. The syndrome consists of regional lymphadenitis, constitutional symptoms, and infrequently organ involvement such as encephalopathy and atypical pneumonia. ...