What antibiotics are used to treat cat bites (animal bites)?

From the Guidelines

Cat bites typically require antibiotic treatment due to the high risk of infection, and the recommended first-line antibiotic is amoxicillin-clavulanate (Augmentin), usually prescribed at 875/125 mg taken twice daily for 5-7 days for adults, as recommended by the Infectious Diseases Society of America 1. The choice of antibiotic is crucial in managing cat bite infections, as cat mouths contain numerous bacteria including Pasteurella multocida, which can cause rapid infection onset within 24-48 hours. Some key points to consider when treating cat bites include:

• The wound should be thoroughly cleaned with soap and water to reduce the risk of infection.
• Medical attention should be sought for proper wound assessment, especially for bites on hands, joints, or face, or if signs of infection develop such as increasing pain, redness, swelling, or drainage.
• Alternative options for those with penicillin allergies include doxycycline (100 mg twice daily), trimethoprim-sulfamethoxazole plus clindamycin, or a fluoroquinolone like ciprofloxacin, as suggested by previous guidelines 1. However, amoxicillin-clavulanate remains the preferred choice due to its broad-spectrum activity against both aerobic and anaerobic bacteria, including Pasteurella multocida 1. It is essential to note that treatment should begin as soon as possible after the bite occurs, ideally within 8 hours, to minimize the risk of infection. In addition to antibiotics, proper wound care and monitoring for signs of infection are crucial in managing cat bites. The high infection rate of 30-50% associated with cat bites underscores the importance of prompt and effective treatment, as highlighted in the guidelines 1.

From the Research

Cat Bite Antibiotics

• The use of antibiotics for cat bites is crucial in preventing infections, particularly those caused by Pasteurella multocida 2.
• Penicillin or amoxicillin is often considered the agent of choice for therapy, but the emergence of beta-lactamase-producing strains and polymicrobial infections has led to the study of alternative antimicrobial agents 2.
• In vitro studies have shown that amoxicillin/clavulanate, cefprozil, cefuroxime, and trimethoprim/sulfamethoxazole are effective against P. multocida isolates 2.

Alternative Antibiotics

• Amoxicillin/clavulanate has been shown to be effective in treating community-acquired respiratory tract infections, including those caused by beta-lactamase-producing pathogens 3.
• The combination of amoxicillin and clavulanic acid has a broad spectrum of antibacterial activity and is effective against a wide range of pathogens, including Streptococcus pneumoniae and Haemophilus influenzae 3, 4.
• However, the use of amoxicillin/clavulanate is associated with a higher risk of gastrointestinal side effects, including Clostridium difficile infection, compared to amoxicillin alone 5.

Antimicrobial Susceptibility

• P. multocida isolates are generally susceptible to most commercial antimicrobial agents, but resistance to sulphonamides, tetracyclines, and aminoglycosides has been reported 6.
• The antimicrobial activity of penicillin, macrolides, and fluoroquinolones has been shown to be effective against P. multocida isolates 2, 6.
• The emergence of resistant strains highlights the need for prudent use of antibiotics and the development of new antimicrobial agents 6, 5.