A study was conducted to assess the efficacy of Valbazen, Levamisole and Dectomax against Haemonchus contortus, using fecal egg count reduction test (FECRT) and egg hatch assay (EHA). Thirty two goats with naturally acquired H. contortus infection were divided into four groups of 8 goats each. Group A was administered Valbazen (@1ml/20 kg BW) while B & C groups were treated with Levamisole and Dectomax @ 5ml/15kg (oral) & 1ml/33kg BW (sub cut), respectively. The D group served as untreated control. Faecal samples were collected on day 0 before treatment and on day 3,7,10 and 14 post treatment. The overall mean percent of fecal egg counts (FECs) on day 10^th and 14^th post treatment showed significant decrease (P<0.05) in fecal egg count. About 91.8% efficacy against H. contortus was recorded in goats with Dectomax followed by Valbazen (88.6%) and Levamisole (83.4%) on day 14^th post treatment suggesting Dectomax as the most effective of the three anthelmintics. The Benzimidazole (pure) was evaluated for its ability to inhibit egg hatching in H. contortus and lethal dose (LD₅₀) was calculated from linear regression. The eggs (200/1ml) were incubated with different concentrations (3.0, 1.5, 0.75, 0.375, 0.1875, 0.0937, 0.0468, 0.0234, 0.0117 and 0.0058 µg/ml) at 22ºC for 48 h. The inhibition of egg hatching at different concentrations ranged from 3.5 to 81.2% and LD₅₀ was 0.1202 µg/ml which is higher than the recommended 0.1 µg/ml. The present data suggest that all the three anthelmintics used in present study showed reduced efficacy against H. contortus in goats than WAAVP level of 95%. Further detailed studies are necessary to clarify the current status of efficacy of three anthelmintics used in the present study.

Key words: Anthelmintics, Dectomax, Egg hatch assay, Fecal egg count reduction test, Haemonchus contortus, Levamisole, Valbazen