Dog Bite Treatment
Immediately wash the wound thoroughly with soap and water for 15 minutes, start amoxicillin-clavulanate prophylaxis for high-risk wounds (especially hand bites, puncture wounds, and wounds presenting >8 hours after injury), ensure tetanus is current, and assess rabies risk based on the animal's vaccination status and ability to observe it for 10 days. 1, 2, 3
Immediate Wound Management
- Irrigate all bite wounds copiously with soap and water for approximately 15 minutes as soon as possible after injury to reduce infection risk and potential rabies transmission 4, 5, 1
- Consider using a virucidal agent such as povidone-iodine solution during irrigation for additional antimicrobial effect 4, 5
- Use high-pressure irrigation with normal saline via a 20-mL or larger syringe to thoroughly cleanse the wound 3, 6
- Carefully examine for deeper structural involvement: assess neurovascular function (pulses, sensation), range of motion of adjacent joints, and probe for tendon, bone, or joint penetration 4, 5, 3
- Pain disproportionate to the visible injury near a bone or joint strongly suggests periosteal penetration requiring extended antibiotic therapy 4, 1
- Remove any foreign bodies and superficial devitalized tissue, but avoid aggressive debridement that enlarges the wound 4
Wound Closure Decision
- Primary closure can be performed for low-risk wounds presenting within 8 hours, particularly facial wounds for cosmetic reasons 4, 7
- A randomized trial demonstrated that primary suturing resulted in significantly better cosmetic outcomes (Vancouver Scar Scale 1.74 vs 3.05) with no increase in infection rates compared to leaving wounds open 7
- Wounds treated within 8 hours had only 4.5% infection rate versus 22.2% for those treated after 8 hours, regardless of closure method 7
- Infected wounds should never be closed primarily 4
- Facial wounds are an exception and can be closed primarily even in higher-risk scenarios if meticulous wound care and prophylactic antibiotics are provided 4
- Consider delayed primary closure or healing by secondary intention for contaminated wounds or those presenting late 4
Antibiotic Prophylaxis
Amoxicillin-clavulanate is the first-line prophylactic antibiotic for dog bites because it covers the polymicrobial flora including Pasteurella species (present in 50% of dog bites), staphylococci, streptococci, and anaerobes 4, 1, 3, 6
High-Risk Wounds Requiring Prophylaxis:
- Hand wounds (highest complication risk due to proximity to joints, tendons, and bones) 5, 1
- Puncture wounds (especially from cat bites, but applies to deep dog bites) 3, 6
- Wounds involving joints, tendons, ligaments, or fractures 1
- Wounds presenting >8 hours after injury 3, 7
- Immunocompromised patients, including those with asplenia or liver disease (at risk for fatal Capnocytophaga canimorsus sepsis) 4, 1
Alternative Regimens:
- For penicillin-allergic patients: doxycycline OR a fluoroquinolone plus metronidazole or clindamycin 5, 1
- Avoid first-generation cephalosporins, penicillinase-resistant penicillins (like dicloxacillin), macrolides, and clindamycin monotherapy as they have poor activity against Pasteurella multocida 5, 1
- For severe infections requiring IV therapy: β-lactam/β-lactamase combinations (ampicillin-sulbactam), piperacillin-tazobactam, second-generation cephalosporins (cefoxitin), or carbapenems 5, 1
- A meta-analysis showed prophylactic antibiotics reduce infection risk (relative risk 0.56), with a number needed to treat of 14 to prevent one infection 8
Rabies Prophylaxis Assessment
The decision for rabies prophylaxis depends on whether the dog can be observed for 10 days and its vaccination status 4, 2
Observation Protocol:
- A healthy domestic dog that bites can be confined and observed for 10 days 4, 2
- Do not begin rabies prophylaxis unless the animal develops clinical signs of rabies during observation 2
- If the dog shows any illness during confinement, it should be evaluated by a veterinarian and reported to public health authorities immediately 4
- If signs of rabies develop, the animal should be euthanized and tested 4, 2
When to Start Immediate Prophylaxis:
- If the dog is rabid, suspected rabid, or unknown/escaped (cannot be observed): begin prophylaxis immediately 2
- Stray or unwanted dogs should either be observed for 10 days or euthanized immediately for testing 4
- An unprovoked attack is more likely to indicate rabies than a provoked attack 4
- A currently vaccinated dog is unlikely to become infected with rabies, though rare vaccine failures have occurred 4
Rabies Prophylaxis Regimen:
- Administer both rabies immune globulin (RIG) and rabies vaccine at different sites for previously unvaccinated persons 4, 2
- Give RIG as soon as possible after exposure, with as much as anatomically feasible infiltrated around the wound 2
- Vaccine schedule: doses on days 0,3,7, and 14 (some older protocols used day 28 as well) 4, 6
- Thoroughly wash wounds for 15 minutes before RIG administration, as wound cleansing alone significantly reduces rabies risk 4
- Bites that do not break the skin generally do not require rabies prophylaxis 3
Tetanus Prophylaxis
- Administer tetanus toxoid (0.5 mL IM) if immunization status is outdated or unknown 4, 1, 3
- Follow standard tetanus prophylaxis guidelines based on wound characteristics and vaccination history 4
Complications to Monitor
Infectious Complications:
- Septic arthritis and osteomyelitis (requiring 3-4 weeks and 4-6 weeks of antibiotics respectively) 4, 1
- Subcutaneous abscess formation and tendonitis 4, 1
- Bacteremia, particularly Capnocytophaga canimorsus in asplenic or cirrhotic patients 4, 1
Non-infectious Complications:
- Nerve or tendon injury/severance 4
- Compartment syndrome 4
- Post-infectious or traumatic arthritis 4
- Fracture and bleeding 4