Integration of halofuginone lactate treatment and disinfection with p-chloro-m-cresol to control natural cryptosporidiosis in calves.

Two field studies were accomplished on a dairy farm in Saxony to compare different strategies for the control of natural cryptosporidiosis in newborn calves. In the first study, 96 newborn calves were allocated to four different groups immediately after birth. Calves of group H and of group HN were treated orally with 120 μg/kg body weight (BW) of halofuginone lactate daily during the first seven days of life. Calves of group C and of group CN were treated with a same volume of tap water. As an additional measure, the pens of groups HN and CN were disinfected with 3% Neopredisan 135-1(®)(p-chloro-m-cresol), the pens of groups C and H remained non-disinfected. Faeces were examined semi-quantitatively for oocyst excretion using carbolfuchsin-staining and the clinical course was recorded. While disinfection alone (group CN) had no effect on oocyst shedding and diarrhoea, treatment with halofuginone lactate (groups H and HN) reduced oocyst shedding and diarrhoea significantly. Combination of treatment and disinfection (group HN) controlled cryptosporidiosis completely during the first two weeks after birth. However, prevalence of diarrhoea and oocyst shedding was higher in the third week of life in group HN than in any of the other groups. This delayed occurrence of cryptosporidiosis was not seen in study 2 when all calves were similarly protected by treatment and specific disinfection. Oocyst shedding was not observed in peripartal cows either by carbolfuchsin staining, ELISA or PCR.