Evaluation of the efficacy of doramectin against an artificial infection of Dictyocaulus viviparus in calves.
Three groups of eight Friesian calves, reared parasite-free, were experimentally infected with 1000 infective larvae of Dictyocaulus viviparus. Two groups were injected subcutaneously with 1% doramectin at 0.2 mg/kg body weight, one group 5 days after infection and the other 25 days after infection. A third group served as untreated controls. Faecal samples were examined for lungworm larvae on days 28, 32, 33, 34 and 35 after infection; the calves were killed and necropsied 39 or 40 days after infection and any lungworms present recovered and counted. Doramectin proved 100% effective against both 5-day-old and mature D. viviparus infections.
Whelan
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NC
Animal Health Services Centre, Massey University, Private Bag 11-222, Palmerston North, New Zealand.
Charleston
W A
WA
Pomroy
W E
WE
Alexander
A M
AM