The patient’s medical history also needs to be closely evaluated. Those who are immunosuppressed because of prior splenectomy or ongoing steroid therapy are at higher risk for complications. Comorbidities, such as diabetes, medication history, and allergies, must be noted. The provider must also inquire about previous therapy for the dog bite. Has the victim sought treatment at an ED or urgent-care center before seeing the primary-care provider? Knowing the extent of previous treatment (especially with regard to antibiotic use) is significant in preventing superinfection with resistant organisms. The American College of Physicians published recommendations for the assessment of dog bites to aid clinicians in providing the proper postexposure course of action.5
Clinicians must be alert to the ABCs, i.e., the examination and maintenance of a patient’s Airway, Breathing, and Circulation. Physical exam begins with the patient’s general appearance and a full set of vital signs to include pain assessment. Vital signs should be frequently re-assessed. Next, examine and assess the bite wound. This begins with a description of the injury location (i.e., face, hands, legs, etc.). If possible, take pictures to help carefully document the wound. If a camera is not available, a hand-drawn diagram will suffice.
Make sure to measure length and depth of the wound and classify it. Classification categories include abrasion, puncture, laceration, avulsion, or crush. Include the amount of devitalized tissue, which helps give an idea as to the extent of injury. Note any injury to other anatomic structures. This includes (but is not limited to) tendon, nerve, bone, and/or ligament damage. Also look for signs and symptoms of infection.
Note any fever, chills, body aches, nausea, vomiting, weakness, pain, erythema, exudates, edema, heat, or foul odors coming from the injury. A thorough neurovascular and musculoskeletal exam (including range of motion) should be performed. Absent pulses distal to a bite wound can indicate vascular injury or be a sign of compartment syndrome.5 Consult a surgeon for more serious wounds (particularly those involving the hand).6 Puncture wounds that appear superficial are often very deep and penetrate deeper anatomic structures. Serious complications can arise quickly if these are not treated adequately.7
Even though thorough history and physical are the cornerstones of the diagnosis and management of dog-bite wounds, ancillary tests can be valuable tools in deciding a plan of action. Consider radiographic evaluation if fracture, presence of foreign body, or infection is suspected. Since the depth of puncture wounds can be deceiving, those close to bones and joints usually require radiographic studies. X-rays are also indicated if the bite has penetrated the joint capsule or if septic arthritis is a concern. Osteomyelitis can be seen on x-ray; however, osteomyelitis usually occurs several days after a dog bite, while septic joints can occur quite rapidly. Consider a referral for vascular evaluation if there is a possibility of vascular injury; crush injuries have a higher propensity for vascular compromise than other wounds.
Culturing the wound is necessary only if infection is suspected. Pasteurella multocida is the most common and most virulent organism responsible for infected dog-bite wounds.4 Infection caused by P. multocida will usually show signs and symptoms within 24 hours. Since different organisms grow at variable rates, wound cultures should be kept for at least seven days. Crush injuries are more likely to become infected than shearing-type wounds.8 If you suspect the infection is systemic, a complete blood count and blood cultures would also be prudent. If compartment syndrome is suspected, wick measurements or arterial line system manometers and other intracompartmental pressure monitors can be used.