Efficacy of toltrazuril 5 % suspension (Baycox®, Bayer) and diclazuril (Vecoxan®, Janssen-Cilag) in the control of Eimeria spp. in lambs.

Sheep coccidiosis is a pathology caused by protozoan parasites of the genus Eimeria spp. with clinical and economic effect especially in young animals (Ambrosi 1995; Pellérdy 1974). A field study was conducted to evaluate the efficacy of a metaphylactic treatment with toltrazuril 5 % suspension (Baycox®, Bayer) in comparison with diclazuril (Vecoxan®, Janssen-Cilag) and untreated controls against naturally acquired Eimeria infections in housed lambs. A total of 170 animals, aged 24 to 34 days and randomly divided in three homogeneous groups, were included in the study. The assessment of treatment efficacy was based on total faecal oocyst excretion (opg) and count reduction (FOCR) in the two groups of animals treated with toltrazuril (TOLT) and diclazuril (DICL) compared with untreated control group (C). The animals treated with toltrazuril showed a considerably lower mean opg to that of group C (5.78 opg versus 144.62 opg) (p < 0.05) and a FOCR of 97.7 %. The higher efficacy (99.23 %) was observed at 15 days post treatment; however, the average efficacy of the drug remained extremely high (> 90 %) for all the study. The lambs treated with diclazuril showed an intense, persistent oocyst excretion with average levels of 97.54 opg, (p < 0.05). This study demonstrates the good efficacy of toltrazuril administered orally to lambs in the prepatent period in subclinical natural Eimeria infections in housed lambs.