A study was carried out to assess the field efficacy of iverme ctin (IVM ) and pyrantel pamoate (PYR) against Parascaris equorum. Seve nty-th ree foals (3– 18 months old) from 5 stud farm s, not treated with anthelmintics in the previous 10 weeks and with individual faecal egg counts (FEC)>200 , were included in the stud y. For each stud farm , 5–7 foals were included in the IVM-treatment group (IVM 0.2% , 200 m cg/kg bod y we ight) or in the PYR-treatment group (PYR 38%, 13.2 mg/kg body weight) and 3 were un treated as controls. For each foal, FECs were carried out before treatment (Day 0) and on Days 7 and 21. An individually based estimation of efficacy was assessed by a bootstrap simulation applied to different previously suggested formulae to evaluate the percent reduction of faecal egg counts (FECR ). Two thousand bootstrap re sample s were constructed from individual FECRs and the parasite population was considered susceptible for FECs 90 and 95% confidence interval (C .I.)95% , suspected resist ant for FECRs comprised between 80 and 90% and 95% C.I.< 95% and resist ant when FECR 80 and 95% C.I.90%. IVM treatment was effective in foals from 2 farms, was equivocal at both stud y times in 1 farm and ineffective in 2 farm s, while PYR was fully effective on all farm s. This data shows that P. equorum -resistant population s are present also in Italy and the phenomenon is spreading in horses throughout Europe.
Field effectiveness of pyrantel and failure of Parascaris equorum egg counts reduction following ivermectin treatment in Italian horse farms.
VERONESI, FABRIZIA;MORETTA, IOLANDA;MORETTI, Annabella;PIERGILI FIORETTI, Daniela;
2009
Abstract
A study was carried out to assess the field efficacy of iverme ctin (IVM ) and pyrantel pamoate (PYR) against Parascaris equorum. Seve nty-th ree foals (3– 18 months old) from 5 stud farm s, not treated with anthelmintics in the previous 10 weeks and with individual faecal egg counts (FEC)>200 , were included in the stud y. For each stud farm , 5–7 foals were included in the IVM-treatment group (IVM 0.2% , 200 m cg/kg bod y we ight) or in the PYR-treatment group (PYR 38%, 13.2 mg/kg body weight) and 3 were un treated as controls. For each foal, FECs were carried out before treatment (Day 0) and on Days 7 and 21. An individually based estimation of efficacy was assessed by a bootstrap simulation applied to different previously suggested formulae to evaluate the percent reduction of faecal egg counts (FECR ). Two thousand bootstrap re sample s were constructed from individual FECRs and the parasite population was considered susceptible for FECs 90 and 95% confidence interval (C .I.)95% , suspected resist ant for FECRs comprised between 80 and 90% and 95% C.I.< 95% and resist ant when FECR 80 and 95% C.I.90%. IVM treatment was effective in foals from 2 farms, was equivocal at both stud y times in 1 farm and ineffective in 2 farm s, while PYR was fully effective on all farm s. This data shows that P. equorum -resistant population s are present also in Italy and the phenomenon is spreading in horses throughout Europe.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
