Human and animal bites

Antimicrobial prescribing: NHS Lothian
NHS Lothian

Do not offer an antibiotic for any bite if the skin is not broken.

Initial Assessment

  • Give appropriate wound care ( including decontamination/irrigation/debridement).
  • Assess if the wound is in a high-risk area including:
    • the hands,
    • feet,
    • face,
    • genitals,
    • skin overlying cartilaginous structures,
    • or an area of poor circulation
  • Assess if the patient is at risk of a serious wound infection because of a co-morbidity (such as diabetes, immunosuppression, asplenia or decompensated liver disease)
  • If wound is obviously infected send tissue/swabs and treat with antibiotics as recommended below.
  • Consider tetanus prophylaxis.
  • Consider rabies see PHE Rabies Risk Assessment.
  • In human bites also assess the risk of HIV, Hepatitis B and Hepatitis C transmission here. The risk of HIV transmission from a human bite is very low and PEP is rarely recommended.

Antibiotic prophylaxis after a bite

Do not offer an antibiotic for any bite if the skin is not broken.

Type of bite Bite has broken the skin but not drawn blood Bite has broken the skin and drawn blood
Human Antibiotics recommended in high risk person or high risk area of the body Antibiotics recommended
Cat Antibiotics recommended in high risk person or high risk area of the body or if a deep bite Antibiotics recommended
Dog or other small animal pet Antibiotics not recommended Antibiotics recommended

 

Recommended duration: 3 days

Recommended antibiotics

 Co-amoxiclav 625mg every 8 hours orally
Penicillin allergy

Doxycycline 100mg every 12 hours orally

AND

Metronidazole 400mg every 8 hours orally

 

Treating an infected bite

Recommended duration: 5 days

Recommended antibiotics

 Co-amoxiclav 625mg every 8 hours orally
Penicillin allergy

Doxycycline 100mg every 12 hours orally

AND

Metronidazole 400mg every 8 hours orally


If extensive infection or patient is unwell ensure blood cultures are taken (10mls in each bottle).

Recommended Antibiotic 

 Co-amoxiclav 1.2g every 8 hours IV
Penicillin allergy (with no severe features)

Ceftriaxone 2g daily IV (*)

AND

Metronidazole 400mg very 8 hours orally (500mg every 8 hours IV if oral route not available)

 

(*) If penicillin allergy includes severe features then contact microbiology.

Notes and information on other animal bites (monkeys, bats, snakes)

Snake bites

Contact National Poisons Information Service - TOXBASE (Tel: 0344 892 0111)

Monkey bites

There is a risk of Herpes virus B infection if bitten by macaque monkeys - discuss with infectious diseases on-call.

Bat bites

Consider the risk of rabies from a bat in any country (including UK) see PHE Rabies Risk Assessment.

Likely organisms

Depends on the species of animal: Usually polymicrobial; can include Pasteurella multocida, Capnocytophaga canimorsus, S.aureus, S.pyogenes, Coliforms, Anaerobes