What is the recommended treatment for a patient with a cat bite, considering potential infection risk and tetanus status?

Cat Bite Treatment

Cat bites require immediate wound irrigation, evaluation for medical care within 24 hours, prophylactic antibiotics (amoxicillin-clavulanate as first-line), tetanus prophylaxis, and rabies risk assessment.

Immediate Wound Management

• Thoroughly irrigate all cat bite wounds immediately with soap and water to reduce bacterial contamination and infection risk 1.
• Running tap water or sterile saline is reasonable for irrigation; povidone-iodine solutions offer no additional benefit 1.
• Explore wounds for depth, tendon or bone involvement, and foreign bodies, particularly in hand wounds which carry the highest infection risk 1, 2.
• Do not suture cat bite wounds unless cosmetically critical (such as facial wounds), as closure increases infection risk in contaminated puncture wounds 1.

Antibiotic Prophylaxis

Amoxicillin-clavulanate is the first-line prophylactic antibiotic for cat bites 1, 3. This recommendation is particularly strong because:

• Cat bites have a 30-50% infection rate, significantly higher than dog bites 1.
• Pasteurella multocida is isolated in 75% of cat bite wounds and is susceptible to amoxicillin-clavulanate 1, 4.
• Cat bites average 5 different aerobic and anaerobic bacteria per wound, including Staphylococcus aureus, Bacteroides, Fusobacterium, and anaerobes 1.
• Hand wounds from cats have the greatest infection risk and warrant prophylactic antibiotics even if presenting early 3, 5.

Dosing and Alternatives

• Amoxicillin-clavulanate: 875/125 mg twice daily for adults 1.
• Alternative oral agents include doxycycline or penicillin VK plus dicloxacillin 1.
• Avoid first-generation cephalosporins (cephalexin), penicillinase-resistant penicillins (dicloxacillin alone), macrolides, and clindamycin as monotherapy due to poor activity against Pasteurella 1.
• For intravenous therapy in severe infections: ampicillin-sulbactam, piperacillin-tazobactam, or carbapenems 1.

Duration of Prophylaxis

• Prophylactic antibiotics for 3-5 days for fresh wounds presenting within 24 hours, particularly deep wounds, hand/foot/face wounds, or in immunocompromised patients 1.
• Do not give prophylactic antibiotics if presenting ≥24 hours after bite without signs of infection 1.

Tetanus Prophylaxis

• Administer tetanus prophylaxis as indicated based on immunization status 1, 3.
• This is a standard component of bite wound management alongside bacterial infection control 1.

Rabies Risk Assessment

Every cat bite requires rabies risk assessment, even from domestic animals 3. Key considerations:

• A fully vaccinated cat is unlikely to have rabies, though rare cases occur 1.
• Unprovoked attacks are more likely to indicate rabies than provoked attacks 1.
• If the cat is available, observe for 10 days; if stray or unavailable, consider rabies prophylaxis 1.
• Postexposure rabies prophylaxis consists of rabies immune globulin (RIG) at presentation plus vaccine on days 0,3,7, and 14 3.
• RIG dose is 20 IU/kg, infiltrated around the wound if anatomically feasible, with remainder given IM distant from vaccine site 1.

When to Seek Immediate Medical Evaluation

Cat bites should be evaluated in a medical facility as soon as possible, particularly if 1:

• Wounds contaminated with saliva require professional assessment.
• Hand, foot, face, or genital area bites warrant urgent evaluation due to higher complication rates 1.
• Deep puncture wounds (common with cat bites) have higher infection risk than superficial wounds 1, 2.

Late Presentation and Complications

Patients presenting >24 hours after cat bite typically have established infection 1, 2:

• Main symptoms include limited painful mobilization, swelling, and erythema around the bite 2.
• Hand wounds presenting late frequently have tendon involvement or purulent flexor tenosynovitis requiring hospital admission 2.
• Mean hospital stay for complicated cat bites is 6 days with need for surgical exploration and IV antibiotics 2.
• Complications include septic arthritis, osteomyelitis, tendonitis, and rarely bacteremia with Capnocytophaga canimorsus or Pasteurella multocida causing septic shock, meningitis, or endocarditis 1, 4.

Critical Pitfalls to Avoid

• Never dismiss cat bites as trivial—they have higher infection rates than dog bites despite appearing less traumatic 1, 2.
• Hand wounds require particular vigilance as they account for the majority of serious complications requiring admission 2, 5.
• Do not use inadequate antibiotic coverage that lacks Pasteurella activity 1.
• Elevation of injured extremity during first few days accelerates healing 1.