Snapshot A 40-year-old woman presents to the emergency room after being bitten by a cat. She had been visiting her boyfriend, who has 5 cats, when one of them was wary of strangers and bit her on the thumb. She cleaned it with some water and soap. On physical exam, she has a normal range of motion and sensation in her thumb. Her pulses are 2+ bilaterally. The wound is irrigated with sterile saline and wound is examined for any foreign bodies. She is started on empiric antibiotics to cover bacteria associated with cat bites. Introduction Classification Pasteurella multocida an facultative anaerobic gram-negative coccobacillus encapsulated can cause cellulitis at the site of inoculation can also cause osteomyelitis Epidemiology incidence high in cat bites demographics male > female more common in those < 20 years of age risk factors cat bites > dog bites bites in the hand deep penetrating wounds immunosuppression Pathogenesis direct inoculation of oral pathogens from animal bites into the wound, leading to infection cats have narrow and sharp teeth, which can inflict deep penetrating wounds with tiny wound openings that prevent good drainage Presentation Symptoms fevers chills Physical exam wound with signs of cellulitis purulence surrounding erythema edema osteomyelitis deep penetrating wound with bone involvement may have a foreign body in the wound Imaging Radiography indication to rule out fracture findings fracture of bone early signs of osteomyelitis soft tissue swelling focal bony lysis or cortical loss blurring of normal fat planes Labs Labs wound culture blood cultures if a systemic infection is suspected catalase positive oxidase positive grows on 5% sheep's blood Making the diagnosis based on clinical presentation Differential Tularemia distinguishing factors associated with rabbits and ticks not with an animal bite presents with skin ulcer and lymphadenopathy Treatment Management approach wounds are not typically closed due to the risk of infection Conservative wound care indication all patients modalities sterile saline irrigation removal of any foreign bodies Medical amoxicillin/clavulanate indication all patients post-exposure prophylaxis indication patients with exposure risk prophylaxis for tetanus rabies Complications Abscess more common with cat bites