Efficacy of abamectin against nematodes in cattle
Heinze-Mutz, E.M.; Pitt, S.R.; Bairden, K.; Baggott, D.G.; Armour, J.; Barth, D.; Cramer, L.G.
Veterinary Record 132(2): 35-37
1993
ISSN/ISBN: 0042-4900 PMID: 8442334 Document Number: 410459
Eight controlled trials were conducted, using 96 cattle of European breeds, to evaluate the efficacy of abamectin against natural and artificially acquired infections by adult and fourth-stage larvae of all the economically important gastrointestinal nematodes and lungworms in Germany and the UK. Half the animals were treated on one occasion with abamectin at a dose of 200 micro g/kg bodyweight given subcutaneously while the other half remained untreated. Worms were counted 14 or 21 days after treatment or 28 days after the last infection. The treatment was highly effective (>99 to 100%) removing immature (L4) stages and adult worms of the following species: Ostertagia ostertagi (inhibited larvae included), Trichostrongylus axei, Haemonchus contortus, Bunostomum phlebotomum, Cooperia species, Oesophagostomum radiatum and Dictyocaulus viviparus. Naturally acquired adult C. surnabada and Trichuris discolor infections were also significantly reduced. For Nematodirus helvetianus the efficacy varied from 89.8 to >99%. Abamectin gave full protection against the gastrointestinal nematodes O. ostertagi, H. contortus, Cooperia species and O. radiatum for at least 7 days and against the lungworm D. vivparus for at least 14 days after treatment.