Because of the likelihood that cat bites will become infected, all persons with a cat bite should be treated with prophylactic antibiotic therapy, although, to our knowledge, no definitive study supports this practice.9 The treatment of infected cat bites requires an understanding of susceptibility patterns of the most common bacteria isolated. Treatment should begin empirically and wound cultures should be obtained. Pasteurella multocida is most susceptible to penicillin, ampicillin, second- or third-generation cephalosporins, doxycycline, trimethoprim-sulfamethoxazole, quinolones, azithromycin, or clarithromycin. It is poorly responsive in vivo to first-generation cephalosporins, antistaphylococcal penicillins, erythromycin, and clindamycin.10 Anaerobes, which are involved in more than two thirds of infections, commonly produce β-lactamase. Thus, initial antibiotic treatment of an infected cat bite should be different from treatment of typical cellulitis. Effective antibiotics include amoxicillin-clavulanate, ampicillin-sulbactam, azithromycin, or a quinolone along with clindamycin. The recommended length of treatment is 10 to 14 days.