II. Epidemiology
- Dog Bites: 4.5 Million/year in U.S. (80-90% of Animal Bites)
- Cat Bites: 400,000 per year in U.S. (5-10% of Animal Bites)
- Human Bites: 250,000 per year
III. Risk Factors: Bite site infection
- Vascular compromise in affected wound
- Distal extremity wounds have diminished vascular supply (Hand bite, Foot Bite)
- Bite site near a prosthetic joint
- Crush injury or Puncture Wound
- Cat Bite (long slender fangs risk deep space infection)
- Delayed presentation
- Arm or leg bite site >6-12 hours
- Facial bite site >12-24 hours
- Diabetes Mellitus or other immunosuppressed state
IV. HIstory
- Injury
- Animal
- Type of animal
- Animal behavior (provoked attack, aggressive behavior)
- Immunization status of animal
- Can animal be observed (e.g. pet or captured)
- Pre-evaluation wound management
- Animal control or police involvement
- Medical History
- Tetanus Immunization status
- Prior Rabies Vaccination
- Immunocompromised status (e.g. Asplenia, Chemotherapy)
V. Exam
- See Hand Exam
- Perform thorough skin exam
- Map bite locations
- Record bite dimensions including depth
- Document wound types (punctures, Lacerations, crush injuries)
- Identify Pitfalls
- Some wounds may not be initially evident (especially in younger children)
- Scalp and skull may hide significant injury under hair, behind ears or in skin folds
- Retained Foreign Body
- Infectious signs (erythema, edema, Lymphadenopathy, drainage)
- Neurovascular injury
- Extremity pulses and Capillary Refill
- Motor and senory exam
- Compartment Syndrome
- Structural injury
- Tendon Injury
- Open Fracture
- Joint penetration
- Facial Injuries (esp. orbital and periorbital wounds)
- Risk of ocular injury
- Proptosis
- Visual changes
- Orbital Cellulitis (and risk of Meningitis, Encephalitis, Brain Abscess)
- Facial Erysipelas
- Some wounds may not be initially evident (especially in younger children)
VI. Imaging
- XRay affected bite site
- Evaluate for Retained Foreign Body (esp. Avulsed Teeth)
- Head Imaging (e.g. Head CT)
- May be indicated in severe bites to the head
- Penetrating skull bites can generate enough force for Skull Fracture (risk of CNS Infection, abscess)
VII. Management: General
- Control bleeding first
- Provide analgesia and Anesthesia
- See Pediatric Analgesic
- Acetaminophen or Ibuprofen
- Consider Intranasal Fentanyl in children
- Dose: 2 mcg/kg intranasal (1/2 in each nostril) via MAD Atomizer
- Inject 1% Lidocaine through intact skin
- Clean wounds with soap and water if not already performed at home
- Copious Wound Irrigation with Normal Saline (or continous tap water irrigation under faucet)
- Set up 1000 ml saline bag with 20 gauge angiocatheter (or 20 ml or larger syringe)
- Place bag into BP cuff and pump up to 300 mmHg
- Irrigate wound with 1000 cc of Normal Saline
- Consider irrigation with dilute Povidone-Iodine solution if the animal is suspected to be rabid
- Do not use excessive pressure (may drive risk of infection to deeper tissues)
-
Wound closure
- Indications for closure by Secondary Intention
- Cat Bite
- Human Bite
- Livestock bites
- Monkey bites
- Puncture Wounds
- Highly contaminated wounds
- Infected wounds
- Wounds older than 24 hours
- Crush wounds with structural injury (urgent Consultation)
- Distal extremity wounds with poor perfusion
- Immunocompromised patients
- Indications for Sutured closure (primary closure)
- Wound less than 12 hours old on extremities
- Wounds located on face less than 24 hours old
- No serious underlying injury
- Scalp Wounds
- Technique
- See Laceration Repair
- Debride devitalized tissue
- Explore wound carefully for associated injuries and foreign body
- Perform single layer closure
- Do not place deep Sutures
- Do not use Tissue Adhesive
- Indications for closure by Secondary Intention
-
Wounds near joint or bone
- Obtain baseline XRay of puncture
- Obtain Orthopedic Consultation
-
Wound exploration
- Explore wound for tendon, joint or bone injury
- Explore wound for foreign bodies (e.g. teeth fragments, which may break off in older animals)
- XRay wound if suspected Radiopaque Foreign Body
- Subspecialty Referral Indications
- Wounds near bone or joint
- Crush wounds with structural injury (e.g. Fracture, tendon Laceration)
- Infected wounds
- Wounds with significant edema
- Neurovascular injury or compromise (emergent Consultation)
- Deep structure involvement (especially on the face, extremities, hands)
-
Immunization
- Tetanus Vaccine
-
Rabies Prophylaxis
- See Rabies Postexposure Prophylaxis for full list of indications
- Indicated if dog or cat with Unknown Vaccination status
- Unprovoked attack
- Animal cannot be quarantined for 10 days
- Do not euthanize animal prior to completion of 10 day observation
- Immediate wound management (see Rabies Prophylaxis)
- Start Vaccine within 48 hours
-
Antibiotic Prophylaxis
- See Bite Wound Antibiotic Prophylaxis
VIII. Prevention
- See Dog Bite
IX. Complications
X. References
- Cowling and House (2017) Crit Dec Emerg Med 31(5): 15-20
- Shivaprakash and Vezzetti (2022) Crit Dec Emerg Med 36(2): 3-10
- Ellis (2014) Am Fam Physician 90(4):239-43 [PubMed]