In the United States, as many as 1% of all pediatric visits to emergency departments during the summer months are for the treatment of human or animal bite wounds, and an estimated 1% to 2% of all bite wounds require hospitalization.1 There are an estimated 4 to 5 million bite occurrences annually. Dog bites constitute the majority of these, at about 80%, with cat bites accounting for 5% to 20%, human bites 2% to 3%, rodent bites 2% to 4%, and other animals comprise the rest. Despite the fewer number of cat bites, they are disproportionately responsible for infections, with the rate of infection after a cat bite reported as high as 50% and the rates of infection after dog or human bites reported at 10% to 15%.2 No matter what type of bite, there is a risk of morbidity and sometimes mortality. Although infection is by far the most common complication, physical trauma certainly plays a role. An average of 10 to 15 deaths occur following dog bites each year in the United States, mostly due to major bleeding and crush injuries following dog bites to the head and neck region.
In general, bite wounds that most often require medical attention are those to the extremities, especially the dominant hand. However, dog bites to the head and neck region are more common in children, and occur in 60% to 70% of attacks in children below the age of 5 years and in 50% of those 5 to 10 years old. This is likely because of the height of a child and the proximity of a child’s head to the mouth of an animal and also because of a child’s generally uninhibited behavior. Males are also more likely than females to sustain a dog bite and bites are usually unprovoked, although for children less than 5 years old, there is no statistical difference between boys and girls getting bitten by dogs.3 In contrast, females and adults are more commonly bitten by cats and 89% of these bites are provoked.4
The time of presentation of the patient to medical care can be telling. Patients who present for medical care within 8 to 12 hours after injury are usually concerned with crush injury, care of disfiguring wounds, or the need for rabies or tetanus therapy. These wounds are frequently contaminated with multiple strains of aerobic and anaerobic bacteria. An estimated 2% to 30% of “treated” wounds will still become infected and may require hospitalization. Patients presenting longer than 12 hours after injury usually have established infection.
In this chapter, both mechanical injury and infection as a result of dog, cat, and human bites are discussed. Included are topics that warrant special consideration, such as clenched-fist injuries, bites to the face, bites to the hand, immunocompromised patients, and rabies. Although other mammalian bites are not discussed, it is of note that monkey and simian ...