. 2021 Sep 9;9(9):e3778. doi: 10.1097/GOX.0000000000003778

Table 8.

Common Pathogens and Subsequent Treatment of Horse Bites

Pathogen	Recommended Treatment	Timing	Route of Administration	Dosage	Notes
Actinobacillus ligniseresii ^118,119	Combination of tetracycline or streptomycin and potassium iodide	3 wk administration of both potassium iodide and tetracycline/streptomycin	Oral or IV for potassium iodide + IM for streptomycin	Potassium iodide: 6–10 g oral or 8 g/kg IV + streptomycin: 30 mg/kg/d for children; 2 g/d for adults¹¹⁹	This organism is extremely rare in humans
		Potassium iodide: daily
		Streptomycin: 2 daily doses; one dose every 12 h¹¹⁸
Streptococcus anginosus ¹²⁰	Vancomycin	2 times a day; 1 dose every 12 h	IV injection	15 mg/kg	Penicillin and clindamycin have begun to show resistance
Streptococcus mutans ¹²¹	Ampicillin¹²²	Every 6 h	Oral	50–100 mg/kg/d for children; 250–500 mg for adults	Various drugs could work such as cefotaxime, but ampicillin has shown best results. Intravenous and intramuscular injection is also possible
Campylobacter ureolyticus ^123,124	Azithromycin¹²³	Daily for 3–10 d as necessary	Typically oral	500 mg	Campylobacter has shown fluroquinolone resistance in some populations. Contraindicated if patient presents with liver or kidney issues¹²⁴
Prevotella melaninogenica ¹²⁵	Metronidazole¹²⁶	Every 6 h for 7–10 d as necessary	Typically oral	7.5 mg/kg	There are many combinations that are possible to treat this bacteria
Prevotella melaninogenica ¹²⁵	Beta-lactam⁴⁴ (eg, penicillin) + beta-lactamase inhibitors⁴⁴ (eg, tazobactam)	Every 6 h for 7–10 d as necessary	Typically oral	7.5 mg/kg
Bacteroides fragilis ¹²⁷	Metronidazole¹²⁶	Every 6 h for 7–10 d as necessary	Typically oral	7.5 mg/kg	This bacterial is resistant to penicillin. Although there have been increasing reports of resistance to metronidizole, it is still the favored treatment
Pasteurella caballi ¹²⁸	Ampicillin¹²²	Every 6 h	Oral	50–100 mg/kg/d for children; 250–500 mg for adults	There are many possible drug options but has shown the least amount of resistance
Yersinia pestis ⁶³	Streptomycin	2 daily doses; one dose every 12 h	IM	30 mg/kg/d for children; 2 g/d for adults
Yersinia pestis ⁶³	Gentamicin	2 daily doses; one dose every 12 h	IM	30 mg/kg/d for children; 2 g/d for adults

IM, intramuscular; IV, intravenous.