Table 1.

Disc strength, zones of inhibition, WHO and OIE rank of each antimicrobial tested.

Antimicrobial Disc	Disc Strength	Zones of inhibition (mm)			WHO rank 2007	OIE rank 2007 (including horses)
		Resistant	Intermediate	Susceptible
Gentamicin	10 mcg	≤ 12	13-14	≥ 15	Critical	Critical
Amoxicillin Clavulanate	20/10 mcg	≤ 13	14-17	≥18	Critical	Critical
Ampicillin	10 mcg	≤ 13	14-16	≥17	Critical	Critical
Cefpodoxime	10 mcg	≤ 17	18-20	≥21	Critical
Ceftiofur	30 mcg	≤ 19	20-23	≥24		Critical
Cefquinome	30 mcg	≤ 19	20-22	≥23		Critical
Chloramphenicol	30 mcg	≤ 12	13-17	≥18		Florphenicol listed as critical Chloramphenicol used as indicator
Ciprofloxacin	5 mcg	≤ 15	16-20	≥21	Critical
Marbofloxacin	5 mcg	≤ 14	15-18	≥19		Critical
Colistin	25 mcg	≤ 14		≥15		Critical
Trimethoprim sulphamethoxazole	(1.25/23.75) 25 mcg	≤ 10	11-15	≥16	Highly important	Critical
Tetracycline	30 mcg	≤ 14	15-18	≥19	Highly important	Critical