Metaphylactic strategies using toltrazuril against coccidiosis in goat kids.

Goat coccidiosis compromises animal welfare, reduces productivity and may cause mortality and delayed growth rates in goat kids around the weaning period worldwide. This field study was conducted to evaluate the efficacy of metaphylactic treatments with two doses of toltrazuril (20 or 40 mg/kg body weight - BW, p. o.), at different timing, in kids naturally infected with Eimeria spp. A total of 97 healthy goat kids (Majorera milk aptitude breed) were divided into five groups, depending on the age of treatment (2 or 7 weeks). One group remained untreated as a negative control until the end of the study. Faecal oocyst shedding, faecal consistency, and body weight of the animals were monitored at day 0 and at weekly intervals. Counts of oocysts per gram of faeces (OPG) were determined by a modified McMaster technique. Morphometric identification of Eimeria species was carried out on individual faecal samples from each experimental group after oocyst sporulation. Goat kids treated at two weeks of age maintained OPG values close to zero during the 5 weeks post-treatment and, overall, had lower faecal oocyst counts than untreated control animals. No significant differences were observed between the two doses of toltrazuril used in two-week-old treated animals. By contrast, when treatment was carried out at seven weeks of age, the dose of 40 mg/kg BW of toltrazuril reduced oocyst levels for longer and to a greater extent than the 20 mg/kg dose. Irrespectively of the treatment and dose, toltrazuril delayed the appearance of pathogenic Eimeria species, i. e. Eimeria ninakohlyakimovae and Eimeria arloingi. As a whole, Eimeria christenseni, with a rather moderate pathogenicity, was highly predominant throughout the study period, including the untreated control group, which was probably the reason why clinical signs of coccidiosis were barely observed throughout the experiment. Under these circumstances, the positive effect of toltrazuril on body weight condition observed in some treated groups was difficult to correlate to the timing and doses. Metaphylactic treatments with 20 mg/kg BW toltrazuril given at two weeks of age are sufficient to control oocyst excretion in goat kids; whereas if administered later in 7-week-old animals, thereby coinciding with the frequently observed peak of oocyst elimination in goat kids under field conditions, a higher dose might be advisable to prevent environmental contamination with infectious oocysts.

Control strategies using diclazuril against coccidiosis in goat kids.

Coccidiosis is probably the main parasitic disease affecting goat kids around the weaning period, leading to high economic losses in goat production due to deaths and delayed growth rates of infected animals. A total of 101 kids of 2-4 weeks of age, naturally infected with Eimeria spp., were divided into five groups and studies were conducted to analyse the effects of metaphylactic administration of diclazuril (Vecoxan®) on parasitological and productive parameters. Two different doses of diclazuril (1 and 2 mg/kg BW, p.o.) were given either at 3 weeks (single treatment) or at 3 and 5 weeks of life (double treatment). The faecal oocyst shedding and the body weights of the animals were monitored at 2-weeks intervals for 6 consecutive weeks. Treatments of goat kids with diclazuril were effective against the three most predominant Eimeria species recorded in this study (E. arloingi, E. ninakohlyakimovae and E. christenseni) and also against other minor species found in faecal examinations, including E. alijevi, E. caprina, E. jolchijevi, E. caprovina, E. hirci and E. aspheronica). In consequence, OPG values lower than 1 × 10(3) were detected in 90 to 100% of the animals up to 15-20 days post-treatment depending on the treatment regimen. Even a single dose of 1 mg/kg BW p.o. resulted in an increase of growth rates in treated animals and therefore should be considered as a control strategy in farms precluding coccidian infections, whilst double and multiple dose treatments could be the recommendation for environments heavily contaminated with Eimeria oocysts. In relation to the OPG reduction and increased growth rates, the severity of the clinical signs (i.e., diarrhoea) was ameliorated in treated animals during the course of infection compared to that of non-treated or control kids. The precise timing of treatment appears crucial in order to prevent severe clinical coccidiosis and thereby enabling the adequate development of protective immune response against Eimeria challenge infections.