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Animal Bites (Mammal): Antibiotics

Animal Bites: Empiric Antibiotics1 
Source of
Bite		 Administration Route First-Line
Therapy

Alternatives for Penicillin Allergic Patients (requires 2 drugs)

For risk stratification see Penicillin ADR (HISTORICAL) Clinical Pathway
For any patient with a low risk for IgE-mediated reaction, consider administering an observed dose
of the first-line therapy and continuing if tolerated OR refer for allergy delabeling

 Duration of Therapy
Dog, cat, or other mammal2 (including human) Oral Amoxicillin-clavulanate
22.5 mg/kg/dose
PO q12h
(max 875 mg/dose)3

Low or high risk for
IgE-mediated reaction

High risk for
severe delayed reaction

 Prophylaxis: 3 days

Treatment: 7 days
OR consult ID for deep infections / bone or joint involvement
Choose one of the following combinations (requires 2 drugs)
AND refer for allergy de-labeling:

(1) Trimethoprim-sulfamethoxazole
5 mg TMP/kg/dose PO q12h 
(max 160 mg TMP/dose)
OR doxycycline 2 mg/kg/dose PO BID
(max 100 mg/dose)

-PLUS-

(2) Clindamycin 10 mg/kg/dose PO q8h
(max 450 mg/dose)
OR metronidazole 10 mg/kg/dose PO q8h
(max 500 mg/dose)		 Both antibiotics are required

(1) Trimethoprim-sulfamethoxazole
5 mg TMP/kg/dose PO q12h
(max 160 mg TMP/dose)
OR doxycycline 2 mg/kg/dose PO BID
(max 100 mg/dose)

-PLUS-

(2) Clindamycin 10 mg/kg/dose PO q8h
(max 450 mg/dose)
OR metronidazole 10 mg/kg/dose PO q8h
(max 500 mg/dose)
IV Ampicillin/sulbactam
50 mg of ampicillin/kg/dose
IV q6h
(max 2000 mg of ampicillin/dose)		 Both antibiotics are required

(1) Ceftriaxone 50 mg/kg/dose IV q24h
(max 2000 mg/dose)

-PLUS-

(2) Clindamycin 10 mg/kg IV q8h
(max 600 mg/dose)		 Consult Infectious Diseases for recommendation

1Adjust antibiotics accordingly if culture and susceptibility results are available.
2Data are lacking to guide antimicrobial use for bites that are not overtly infected from small mammals, such as guinea pigs and hamsters.
3Utilization of either a 7:1 or 4:1 ratio product is recommended. Can consider high dose amoxicillin-clavulanate (45 mg/kg/dose PO BID - max 2g/dose) for facial bites, especially if puncture into sinuses where pneumococcus may be involved. Utilize 14:1 and 16:1 formulations if using high dose regimens.

Additional notes:

  • Coverage for methicillin-resistant Staphylococcus aureus (MRSA) is not routinely recommended but may be considered for (1) patients with an abscess, (2) patients with MRSA history or risk factors, or (3) severe bites. Doxycycline should be a component of the regimen if MRSA is a concern and combined with amoxicillin-clavulanate or clindamycin or metronidazole.

  • *Data are lacking to guide antimicrobial use for bites that are not overtly infected from small mammals, such as guinea pigs and hamsters.

References:
Lexicomp. (n.d.). Amoxicillin: Dosage & administration. In Lexi-Drugs Online. Retrieved November 11, 2024, from https://online.lexi.com

Kimberlin, D. W., Barnett, E. D., Lynfield, R., & Sawyer, M. H. (Eds.). (2021). Bite wounds. In Red Book: 2021–2024 Report of the Committee on Infectious Diseases (32nd ed.). American Academy of Pediatrics. https://doi.org/10.1542/9781610025782-S2_008

These pathways do not establish a standard of care to be followed in every case. It is recognized that each case is different, and those individuals involved in providing health care are expected to use their judgment in determining what is in the best interests of the patient based on the circumstances existing at the time. It is impossible to anticipate all possible situations that may exist and to prepare a pathway for each. Accordingly, these pathways should guide care with the understanding that departures from them may be required at times.

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Evidence Based Practice / Clinical Pathways
Clinical Practice Guidelines, Care Process Models, and Enhanced Recovery After Surgery Pathways
Animal Bites (Mammal)
Animal Bites (Mammal): Antibiotics