Persistent efficacy of moxidectin against Dictyocaulus viviparus and Ostertagia ostertagi in cattle
Hubert, J.; Kerboeuf, D.; Cardinaud, B.; Blond, F.
Veterinary Record 136(9): 223-224
1995
ISSN/ISBN: 0042-4900 PMID: 7771074 Document Number: 449416
Groups of 5 weight-matched groups of Monbeliard calves (5 months old; 173 kg body weight) were injected with moxidectin 1% solution (0.2 mg/kg s.c.) at 42, 35, 28, 21 or 15 days before oral infection with Dictyocaulus viviparus and Ostertagia ostertagi larvae. One group remained untreated. The calves were killed 21 or 22 days after infection and abomasa and lungs were examined for parasites. No adverse reactions to moxidectin were seen. Up to 35 days after treatment the efficacy of moxidectin, measured by the arithmetic mean worm burden of treated groups compared with that of controls, was 100% for D. viviparus and more than 99% for O. ostertagi. In the group treated 42 days before infection only 2 calves harboured D. viviparus and O. ostertagi worms, the other calves were worm-free. No fourth stage larvae were found. It is suggested that the results could provide a basis for extending the interval between treatments in prophylactic nematode control programmes after turn-out.