What is the recommended acute management of a dog or cat bite, including wound irrigation, tetanus and rabies prophylaxis, and appropriate antibiotic therapy?

Dog and Cat Bite Management

Immediately irrigate all dog and cat bite wounds with copious amounts of running tap water or sterile saline, administer amoxicillin-clavulanate 875/125 mg twice daily for prophylaxis (especially for hand wounds, puncture wounds, or wounds presenting >8 hours after injury), ensure tetanus prophylaxis is current, and evaluate rabies risk based on the animal's vaccination status and behavior. 1, 2

Immediate Wound Care

Irrigation is the single most critical intervention to prevent infection:

• Irrigate thoroughly with running tap water or sterile normal saline until all visible debris is removed 1, 2
• Use a 20-mL or larger syringe to generate adequate pressure (approximately 15 psi) for effective bacterial decontamination 2, 3
• Running tap water is as effective as sterile saline and superior to antiseptic solutions like povidone-iodine 1, 4, 5
• Remove only superficial debris; avoid aggressive debridement that could enlarge the wound 1, 2
• Do NOT use iodine- or antibiotic-containing irrigation solutions 1, 2

Critical pitfall: Animal bite wounds contaminated with saliva require immediate medical evaluation regardless of apparent severity 1

Antibiotic Therapy

Amoxicillin-clavulanate is the first-line antibiotic for both dog and cat bites:

• Oral regimen: Amoxicillin-clavulanate 875/125 mg twice daily 1, 2
• This provides essential coverage against Pasteurella multocida (present in 50% of dog bites and 75% of cat bites) and mixed aerobic/anaerobic oral flora 1, 2

Mandatory indications for prophylactic antibiotics: 1, 2

• Hand wounds (highest infection risk)
• Puncture wounds (especially cat bites)
• Wounds presenting >8 hours after injury
• Wounds near joints or bones
• Immunocompromised patients
• Wounds with crush injury or devitalized tissue

Alternative oral regimens for penicillin allergy: 1, 2

• Doxycycline 100 mg twice daily
• Fluoroquinolone (ciprofloxacin, levofloxacin, or moxifloxacin) PLUS metronidazole or clindamycin for anaerobic coverage

Avoid these antibiotics (poor activity against Pasteurella): 1, 2

• First-generation cephalosporins (cephalexin)
• Macrolides (erythromycin)
• Clindamycin alone
• Penicillinase-resistant penicillins (dicloxacillin) alone

Intravenous therapy for severe infections: 1, 2

• Ampicillin-sulbactam, piperacillin-tazobactam, or carbapenems (ertapenem, imipenem, meropenem)
• Extended duration: 4-6 weeks for osteomyelitis, 3-4 weeks for septic arthritis 1, 2

Wound Closure Decisions

Most bite wounds should NOT be closed: 2

• Allow healing by secondary intention for the majority of dog and cat bites
• Exception: Facial lacerations may be closed primarily after meticulous irrigation and with concurrent prophylactic antibiotics 1, 2
• Clean wounds presenting <8 hours can be approximated with Steri-Strips if needed 2
• Never close: Infected wounds, wounds with purulent discharge, or wounds presenting >8 hours after injury 1, 2

Critical pitfall: Cat bites appear deceptively minor but have higher rates of deep infection, osteomyelitis, and septic arthritis than dog bites due to narrow, deep puncture wounds 1

Tetanus Prophylaxis

Administer tetanus toxoid for all bite wounds: 1, 2

• Give 0.5 mL intramuscularly if vaccination status is outdated or unknown
• Booster required if >5 years since last dose for contaminated wounds (all animal bites qualify)
• Booster required if >10 years since last dose for clean wounds

Rabies Risk Assessment and Prophylaxis

Rabies evaluation depends on animal behavior, vaccination status, and geographic location: 1, 2

Low-risk scenarios (prophylaxis generally NOT needed): 2

• Domestic dogs or cats with documented current rabies vaccination
• Animal available for 10-day observation period and remains healthy
• Provoked bite from healthy-appearing pet

High-risk scenarios requiring prophylaxis: 1

• Unprovoked attack
• Animal unavailable for observation or testing
• Feral, stray, or wild animal
• Animal exhibiting abnormal behavior
• Geographic areas with endemic rabies

Rabies postexposure prophylaxis regimen for previously unvaccinated persons: 1

• Day 0: Rabies immune globulin (HRIG) 20 IU/kg body weight—infiltrate full dose around and into wounds if anatomically feasible, inject remainder intramuscularly at site distant from vaccine
• Days 0,3,7,14, and 28: Rabies vaccine (HDCV, RVA, or PCEC) 1 mL intramuscularly in deltoid (adults) or anterolateral thigh (children)
• HRIG can be given up to day 7 if not administered initially 1
• Never administer HRIG and vaccine in same syringe or same anatomical site 1

Previously vaccinated persons: Receive only vaccine on days 0 and 3 (no HRIG needed) 1

Special Considerations by Bite Type

Cat bites are more dangerous than they appear: 1, 2

• Higher proportion of deep infections (65% anaerobes vs 50% in dog bites)
• Higher rate of Pasteurella multocida (75% vs 50%)
• Greater risk of osteomyelitis and septic arthritis despite less visible tissue damage
• Puncture wounds penetrate deep structures (tendons, joints, bone) with minimal surface trauma

Dog bites have more visible trauma: 1

• More crush injury and tissue damage
• Lower infection rate than cat bites overall
• Hand wounds remain highest risk regardless of animal type

Adjunctive Measures and Follow-Up

Supportive care accelerates healing: 1, 2

• Elevate injured extremity, especially if swollen
• Pain disproportionate to injury near bone or joint suggests periosteal penetration—requires imaging and specialist evaluation 1

Mandatory follow-up: 2

• Contact within 24 hours (phone or office visit) for all outpatients
• Return immediately for increasing pain, redness, swelling, purulent discharge, or fever 1

Indications for hospitalization: 2

• Infection progressing despite appropriate oral antibiotics
• Deep tissue involvement or suspected osteomyelitis/septic arthritis
• Immunocompromised patient with signs of infection
• Inability to comply with outpatient treatment

Critical pitfall: Hand wounds and clenched-fist injuries require expert hand surgery evaluation due to high risk of tendon, joint capsule, or bone involvement 1