First Report of Anthelmintic Resistance in Gastrointestinal Nematodes of Sheep from Costa Rica

Table 2

Gastrointestinal nematode egg count percent reduction after treatment with ivermectin in seven flocks from Costa Rica.

Farm	Control		Albendazole		Percentage of reduction	CI 95%		Drench effectiveness
	n	𝑋 epg	n	𝑋 epg		Lower	Upper
A	15	1977	15	317	84	49	95	Resistant
B	10	570	12	46	92	80	97	Resistant
C	11	250*	12	58	77	17	93	Resistant
D	13	608	14	307	49	−2	75	Resistant
E	13	100*	14	7	93	28	99	Resistant
F	14	2593	15	87	97	89	99	Suspicious
G	15	1700	15	60	96	88	99	Suspicious

*These flocks were 300 or more epg in the pre-treatment phase.