Cat bites or bite

• cat bites that present to medical attention tend to be puncture wounds rather than lacerations (as the latter are easier to clean effectively and so are less likely to become infected)
  • cat bites are commonly on the hands and arms
  • up to two-thirds of cat bites will give rise to infections (1)
  • Pasteurella spp are isolated in around 75% of infected cat bites
    • wide variety of other aerobic and anaerobic organisms may also be present in infected wounds
    • most infections from animal bites are polymicrobial and contain both aerobic and anaerobic organisms. Causative organisms for infections from cat and dog bites (the most common animal bites) include Pasteurella, Streptococcus, Staphylococcus, Neisseria, Corynebacterium, Fusobacterium nucleatum and Bacteroides (2)
      
      
  • serious complications occur in up to 30% of patients with infected wounds
    • especially when puncture wounds are over or near a joint (especially on the hands), in which case, osteomyelitis or septic arthritis may occur
    • 'Cat scratch disease' can follow a bite or scratch from a cat or dog
      • caused by Bartonella henselae, a Gram-negative bacillus
        • typically presents with an erythematous papule (usually 3-10 days after the injury), regional lymphadenopathy, and prolonged non-specific systemic symptoms, such as fever, headache and fatigue
        • generally, the condition is mild and resolves within 2 months - however sometimes it may complicated by pneumonia, encephalitis or hepatitis (especially among patients with AIDS) or, rarely, by ocular complications, in which case, specialist ophthalmological advice should be sought

NICE suggest (2)

• antibiotic prophylaxis is not needed if a cat bite has not broken the skin. However, it can be considered if the cat bite has broken the skin but not drawn blood if, despite appearances and the lack of blood, the wound could still be deep

General wound closure considerations (3)

• small wounds
  • may be left open to heal by secondary intention with daily non-stick dressing changes until the skin has re-epithelialised
• gaping wounds
  • can be approximated and closed after copious irrigation and debridement
• wounds to the face from any animal
  • can be closed (for cosmesis; the face has no higher risk of infection than elsewhere)
• feline (cat) bite
  • should avoid closing all non-facial wounds
• canine (dog) bites
  • majority can be closed except in the hands or feet, where infection risk is much higher
• human bites
  • should avoid closing non-facial wounds or facial wounds more than 24 hours after injury
  • requires follow up with a plastic surgeon
• puncture wounds
  • have an especially high risk of infection
  • should let all puncture wounds heal by secondary intention (after irrigation)

Reference:

1. Drug and Therapeutics Bulletin (2004);42:65-72.
2. NICE (November 2020). Human and animal bites: antimicrobial prescribing
3. Colmers-Gray I N, Tulloch J S, Dostaler G, Bai A D. Management of mammalian bites BMJ 2023; 380 :e071921 doi:10.1136/bmj-2022-071921