Practice Essentials
Animal bites are not uncommon occurrences. However, patients who are treated in emergency centers represent only a small percentage of all bite victims. Although notification is mandatory in many states, an estimated 50% of all dog bites are not reported. [1] See the image below.
The child in this photo sustained a dog bite to the face. Courtesy of Wikimedia Commons, Tanner Ford, TRFPhotography.
Most animal bites are dog bites (80-90%). Cat bites make up approximately 10%, and bites from miscellaneous animals and rodents also contribute to these figures.
Most animal bites occur on the extremities, but the head and neck region is also often affected. Animal bites to the face are most commonly made by dogs or cats. Of all dog bites, 9-36% occur to the head and neck region. The head and neck region is injured in 6-20% of persons who sustain cat bites. Children are injured more frequently in the head and neck region than adults.
Most bites occur in the summer months in the late afternoon. Additionally, most bites occur in the victim's home or in the home of a friend or relative. Often, the animal is known to the victim (eg, a pet). Indeed, a retrospective study by Kumar et al indicated that in pediatric patients, dog bites to the head, face, and neck requiring neurosurgical consultation often are inflicted by the family pet, in most cases a large-breed dog who has manifested no previous incidents of aggression. In such patients, according to the study, the cranial vault is commonly injured, with the most frequent injury being depressed skull fracture. [2]
Workup in animal bites to the head and neck
Routine laboratory studies are not mandatory in the workup following an animal bite. However, with the risk of infection or sepsis, a complete blood count and cultures may provide useful information for treatment.
Imaging studies are not routinely performed, except for possible fractures. An imaging study may be helpful in identifying the presence of a foreign body (eg, a tooth).
Management of animal bites to the head and neck
Medical care
Thorough cleansing is adequate for contused, intact skin. If the skin is penetrated, copious irrigation is warranted. Debridement is then required to remove any devitalized tissues resulting from the crush injury of the bite.
In children, primary immediate closure of facial dog bite injuries with antibiotic coverage is suggested. [3]
Basic wound management is the sine qua non of therapy for animal bites. Treatment may include debridement, antibiotic therapy, supportive care, and, possibly, primary suturing or hospitalization with operative debridement.
Tetanus toxoid is administered, and the rabies status of the animal is investigated. In the event of possible rabies exposure, human diploid vaccine can be administered.
Obtain wound cultures to guide antibiotic therapy. Blood cultures are necessary if signs of a systemic infection are present. Drain any collections.
Initial wound care mandates vigorous cleansing. This is accomplished easily with copious saline lavage under pressure. Puncture wounds also require copious lavage. Irrigation with povidone-iodine solution (Betadine) also may have an antiseptic effect.
Surgical care
Laceration injuries can be closed primarily, but avulsion injuries may benefit from delayed treatment. Injuries with significant tissue loss may require local flap treatment, composite grafts, or even vascularized flaps. Debridement of devitalized tissues in the head and neck region must be performed with care.
Pathophysiology
Although the risk of infection exists in any bite situation and proper wound management is required, animal bites to the head and neck require special considerations. The intimate juxtaposition of vital structures and the cosmetic issues of the head and neck region warrant special care for animal bite wounds to these areas.
Epidemiology
Frequency
United States
Animal bites account for 1% of the emergency department visits in the United States. Up to 4.5 million people are treated for animal bites each year, and children and adults in the United States together suffer an estimated 400,000 cat bites and 4.5 million dog bites, annually. [4]
Using the Nationwide Emergency Department Sample, however, Holzer et al determined that between 2010 and 2014, the United States saw a reduction in the overall prevalence of dog bite injuries. [5]
Dixon and Mistry noted that after institution of a statewide stay-at-home order as a result of the coronavirus disease 2019 (COVID-19) pandemic, the rate of dog bite–related visits to the pediatric emergency department of their Colorado children’s hospital nearly tripled. Subsequent to relaxation of the restrictions, the investigators reported, the rate of such visits remained high. [6]
International
In studies from England and Scotland, animal bite injuries account for 3% of emergency department visits. In Switzerland, up to 23,000 people are treated for animal bites and scratches annually.
Mortality/Morbidity
Animal bites can lead to infection. Approximately 20% of dog bites in children become infected; the rate of infection of cat bites in children varies, but can reach 50%. [4] This consequence can be avoided, however, with appropriate treatment.
Other animal bite complications include sepsis, osteomyelitis, septic arthritis, and even death. Fatalities are uncommon, but an average of 10-15 deaths occur following dog bites each year in the United States. Most of these fatalities are children who sustain bites to the head and neck region. Even a minor bite to a major vessel can lead to hemorrhage in a small child. Skull fractures resulting from dog bites have been reported.
A study by Garvey et al of morbidity in pediatric dog bites, using data from a level one pediatric trauma center, found that 69% of patients required surgery. According to the report, which involved 282 pediatric patients (median age 5 years), surgical procedures included laceration repairs (76%), tissue transfers (14%), and neurosurgical operations (2%), with the most severe traumas consisting of laryngotracheal transection, intracranial hemorrhage, depressed skull fracture, and bilateral orchiectomy. No deaths occurred among the study’s patients. [7]
A Swiss study of dog bites indicated that wounds to the hand are at particular risk of developing secondary infectious complications. This may relate to the proximity of bradytrophic tissue, such as the tendons, to the surface of the skin, and a lack of natural anatomic barriers in the hand, which allows infection to spread. [8]
A prospective, multicenter, observational study by Tabaka et al indicated that among patients with dog bite wounds, those with puncture wounds or wounds that are closed during treatment have a high infection risk and should be considered for prophylactic antibiotic therapy. The study involved 345 dog bite patients, 18 of whom (5.2%) developed wound infections. [9]
A study by Babovic et al of 193 patients who had suffered a cat bite injury indicated that risk factors for hospitalization following a cat bite include the following [10] :
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Smoking
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Immunocompromised state
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Wound location over a joint or tendon sheath
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Erythema and swelling at presentation
The investigators did not find evidence that the length of time between bite and presentation affected the likelihood of hospitalization. They also found no link between hospitalization and the patient’s white blood cell count, C-reactive protein values, and erythrocyte sedimentation rate. [10]
Race
Epidemiologic data have failed to demonstrate an association between race and bites.
Sex
In general, animal bites occur with equal incidence in men and women. However, dog bites occur more frequently in men and boys, while cat bites occur more frequently in women and girls. The aforementioned study by Holzer et al found the likelihood of presenting with a dog bite to be particularly high among males diagnosed with an externalizing behavior disorder. [5]
Age
Animal bites occur more frequently in adults. However, children have a higher percentage of head and neck bites. Additionally, bites in children are more likely to warrant medical attention.
In a retrospective study of dog bites in the United States, Tam et al found that of pediatric patients (those aged 12 years or younger) admitted to a hospital with dog bites between 2015 and 2017, 78.1% and 4.8% had facial injuries or facial fractures, respectively, compared with 29.3% and 2.5%, respectively, of older patients. The rate of facial bone surgical procedures in the younger patients was 1.3%, versus 0.5% in those aged 13 years or older. [11]
Breed
The breed of the dog has been reported for some bites. Most bites (>50%) are inflicted by working dogs, which includes German shepherds, Doberman pinschers, collies, Great Danes, huskies, and mixed shepherd-type dogs. Sporting dogs, such as spaniels, retrievers, pointers, and setters, are implicated less frequently. Cats are not typically identified by breed.
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The child in this photo sustained a dog bite to the face. Courtesy of Wikimedia Commons, Tanner Ford, TRFPhotography.
