The development of protective immunity against gastrointestinal nematode and lungworm infections after use of an ivermectin bolus in first-year grazing calves

Therapeutic and prophylactic efficacy of the Ivomec SR Bolus against nematodes and Psoroptes ovis in cattle weighing more than 300 kg at the time of treatment

“…Similar results were achieved in studies using a slowrelease bolus delivering 12 mg of ivermectin per day in calves weighing 100±300 kg at the time of treatment (Rickard et al 1991;Claerebout et al 1994;Williams et al 1995;Yazwinski et al 1995;Jacobsen et al 1996;Schnieder et al 1996). The spectrum of nematode species in which signi®cant dierences could be established between Ivomec SR Bolus-treated and untreated cattle covers all economically important helminth parasites of animals of this age group.…”

“…The device is designed to deliver ivermectin at 12 mg/day for 135 days (Zingerman et al 1992). Studies performed with dierent prototype boluses designed to release ivermectin at a rate of 8±12 mg/day have indicated that ivermectin delivered by sustained release eectively removes existing infections and prevents establishment of gastrointestinal and pulmonary nematodes (Baggott et al 1986(Baggott et al , 1994Egerton et al 1986;Alva-Valdes et al 1988;Soll et al 1988;Rickard et al 1991;Zimmerman et al 1991;Williams and Plue 1992;Claerebout et al 1994;Williams et al 1995;Yazwinski et al 1995;Pitt et al 1996;Schnieder et al 1996) and also provides ecacy against mange mites, sucking lice and Hypoderma larvae (Merck, unpublished data).…”

Deep insights into Dictyocaulus viviparus transcriptomes provides unique prospects for new drug targets and disease intervention

“…Traditionally, the control of Dictyocaulus infection and dictyocaulosis has been based on the prophylactic administration of an irradiated larval vaccine (Jarrett et al, 1960) or anthelmintic drugs, such as macrocyclic lactones (Schnieder et al, 1996; Ploeger, 2002). However, the disadvantages of the current (live) vaccination strategies (i.e., instability of the irradiated larvae and inability to confer a sterile immunity and a life-long protection; McKeand, 2000), the unsuccessful attempts to develop a recombinant vaccine and recent reports of emerging anthelmintic resistance (Matthews et al, 2001; Ploeger, 2002; Molento et al, 2006) are driving the search for new intervention targets.…”

LongRange™ (eprinomectin 5%) extended-release injection parasiticide and the utility of extended-activity antiparasitics in cattle

“…This issue has been addressed in a number of studies and the consensus is that animals treated in their first grazing season may display some reduced immune protection when subsequently artificially challenged with high infective doses of larvae. However, under normal husbandry conditions, second grazing season cattle (and adult cows) are exposed to only low levels of over-wintered larvae following turn-out in the Spring and consequently no significant negative effects on the occurrence of clinical disease or growth performance have been observed (Armour, 1989;Claerebout et al, 1998;Larsson et al, 2011;Schnieder et al, 1996;Taylor et al, 1995a;Vercruysse et al, 1995).…”