Related Subjects:
|Pasteurella Multocida
|Capnocytophaga canimorsus
|Snake Bites
|Dog Bites
|Tetanus
Increasingly, dog bites are the subject of litigation because bite wounds are still being sutured when they should be left open and because of incorrect antimicrobial prophylaxis. Flucloxacillin or Erythromycin are inapporpiate choices.
About
- With dog bites leg and hand wounds are at higher risk for infection
- They should be handled with extra caution
- Bite wounds are considered tetanus prone
- Capnocytophaga canimorsus sepsis can follow a trivial bite
Incidence
- Over 250,000 attendances per annum at ED in UK
- Those with splenectomy and on steroids or immunocompromised at higher risk of sepsis
Aetiology
- Huge variety of biting force between dog breeds
- 310 kPa to nearly 31 790 kPa in specially trained attack dogs
Organisms
- Consider Rabies in those bitten abroad
- Dog bites: polymicrobial, Pasteurella and Bacteroides spp.
- Infected bites < 12 hours after injury usually Pasteurella spp
- Infected Bites > 12 hrs usually staphylococci or anaerobes
- Pasturella Multocida is virulent and can cause severe infection. Aggressive gram negative pathogen causing severe inflammatory response. Resistant to flucloxacillin and erythromycin.
Risks
- Alcoholics : Pasteurella infection
- Cirrhosis/Asplentia: Capnocytophaga canimorsus is a bacterium of the normal oral flora of dogs and cats.
- Steroid therapy, rheumatoid arthritis, diabetes mellitus, and lymphoedema after radiotherapy (all increase risk of Pasteurella infection)
Clinical
- Children with facial or head bites need cervical immobilisation to exclude neck injury
- Assess size and depth and any remaining foreign bodies e.g teeth
- Assess muscle, tendon and nerve and soft tissue and bone damage
- Hand bites are more prone to infection
Investigations
- FBC, CRP, U&E in those with infection or systemic disease
- X-Ray to exclude fractures, teeth or retained foreign bodies
Management
- Full and thorough and vigorous wound cleansing and irrigation are presumed with saline or tap water and remove any foreign bodies and give tetanus cover is given and debridement as needed. Delayed closure is recommended. Raise and immobilise would if swelling. Give antibiotics if risk of infection.
- If the wound is infected or becomes infected with pus take wound swabs and arrange any drainage and antibiotics. It is prudent to wound check within 1 to 2 days after the bite. Early follow-up is particularly important when the risk of a Pasteurella infection is high.
- Coverage of P. multocida should be included. Co amoxiclav is an excellent first-line agent and covers Staph Aureus and anaerobes and Pasteurella. Others are Doxycycline + Metronidazole. For active infection a 2 week course may be needed.
- Where rabies is a possibility assess for Rabies vaccine and immunoglobulin should be given if required