Catbite or scratch injuries frequently contain mixed organisms, and penicillin or erythromycin alone may not give adequate coverage, as shown in the cases described. Incision and drainage should not be neglected or deferred when a deep infectious process is present or bones, joints, or tendon sheaths are involved. Finally, a catbite injury is a deep penetration injury with potentially virulent organisms that require close followup and awareness of potential problems.