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The therapeutic efficacy and prophylactic activity of doramectin against Dictyocaulus viviparus in cattle
Author(s) -
BARTON NJ,
MITCHELL PJ,
HOOKE FG,
REYNOLDS J.
Publication year - 1995
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1995.tb07540.x
Subject(s) - doramectin , biology , veterinary medicine , zoology , medicine , ivermectin
SUMMARY Three groups of 8, 4‐month‐old male Jersey or Jersey‐cross calves were infected with 2400 Dictyocaulus viviparus L 3 larvae and either left untreated or injected subcutaneously with 200 μg/kg doramectin 5 or 25 days after infection (DAI). Lungworms were found in all untreated cattle (geometric mean = 49) at necropsy 39 or 40 DAI. None was found in any of the treated cattle. In a second experiment, groups of 6, 8‐month‐old calves were untreated or injected with 200 μg/kg doramectin 28, 21 or 14 days before each calf was challenged with 2700 D viviparus larvae. Lungworms were recovered at necropsy 32 to 34 DAI. The geometric mean worm burden in the untreated cattle was 550. This was reduced by 100%, 99.5% and 94.1% in calves treated with doramectin 14, 21 or 28 days, respectively, before infection. It was concluded that doramectin is a highly effective anthelmintic against D viviparus adult or L 4 infections of cattle, and that reinfection of treated cattle will be significantly reduced for at least 28 days after treatment.