Dog Bite

Worldwide, Dog Bites are the most common cause of Rabies
1. Rabies is responsible for 59,000 deaths worldwide per year
Incidence in United States: 4 to 4.5 Million bites per year
1. Rate: 103-118 per 100,000 people in U.S.
2. Over 330,000 Emergency Department visits per year
3. Dog Bites account for 80-90% of Animal Bites in U.S.
4. Unprovoked Dog Bites account for 50% of events
5. Dogs are known to the victim in 70% of Dog Bite cases
Mortality: >12 per year in U.S. (most are children)
1. Pit bulls accounted for 44% fatalities 1979-1988
2. Rottweilers are also responsible for many of the fatalities
Infection rate: 15-20%
Children are more likely than adults to sustain bites (esp. school age males)
1. Preschool children are typically bitten by their family dogs at home
2. Teens are typically bitten by dogs unknown to them outside the home

Crush or avulsion injuries are more typical from Dog Bite
1. Extensive Lacerations and soft tissue avulsions are most common
Jaw of a dog can generate pressures up to 450 psi (some report up to 1800 psi)
1. Occult Fractures may occur with high compression forces
Foreign body risk
1. Dog Bites may leave tooth fragments in wounds
2. Carefully examine wounds and consider xray for Retained Foreign Body

Head and Neck (15% of Dog Bites)
1. Typical site for Dog Bites in young children, especially ears
Extremities (arms account for 60% of Dog Bites)
1. Typical site for Dog Bites in adolescents and adults
2. Perform a careful Hand Exam (esp. Hand Neurovascular Exam)
  1. Occult hand tendon injuries are common

Imaging is not routinely needed in most Dog Bites
Extremity
1. Consider XRay imaging in extensive, deep wounds to evaluate for Fractures and retained foreign bodies
Head and Face
1. Consider imaging if deformity identified

Update Tetanus Vaccination as needed
Perform wound cleaning, copious Wound Irrigation, and foreign body and devitalized tissue Debridement
1. See Animal Bite for irrigation and general management
Antibiotics
1. See Dog Bite Infection for Antibiotic selection
Confirm dog has up to date Vaccinations including Rabies
1. Start Rabies Prophylaxis if Rabies status cannot be confirmed
2. Alternatively, quarantine healthy dog and observe for 10 days
  1. Necropsy for Rabies if dog dies or shows signs of Rabies during 10 day observation
Wound Repair
1. Safe to repair all Dog Bite wounds (regardless of location) presenting within 8 hours of bite injury
  1. Infection rates increase significantly after 8 hours (22% infection rate versus 4.5%)
  2. Bite wounds treated with primary closure should be treated with Antibiotics (see Dog Bite Infection)
2. Inform patient of risks of infection, closure options
  1. Primary closure results in significantly better cosmetic results than secondary closure
  2. Dog Bite Infection rates are similar regardless of management
    1. Primary closure (6-9.7%)
    2. Secondary closure (6.9%)
3. References
  1. Chen (2000) Acad Emerg Med 7(2): 157-61 [PubMed]
  2. Paschos (2014) Injury 45(1): 237-40 [PubMed]

Significant morbidity and mortality worldwide (esp. children)
Dog Bite Infection (see below)
Retained tooth fragments
Chronic Scars (50% of Dog Bites)
Posttraumatic Stress Disorder
1. Short-term Nightmares or avoidance is common (seek medical attention if they persist)
Rabies
Tetanus

Outpatient Wound Check in 24-48 hours Indications
1. Usually indicated over inpatient care
2. All hand wounds should be rechecked

Do not approach an unfamiliar dog
Do not disturb a dog eating or sleeping
Do not disturb a dog caring for puppies
When approached by a dog
1. Never scream near a dog
2. Never run from a dog
  1. Be still (Like a tree)
  2. If you fall, become a log
3. Allow the dog to first sniff you before petting him
4. Do not make direct eye contact with the dog
Reporting guidelines
1. Report Dog Bites to an adult immediately
2. Report stray dogs or unusual behavior immediately