Eradication of Chorioptes bovis mange in a dairy herd with turnout to graze by eprinex pour-on

摘要

The possibility to control or even eradicate chorioptes mange by a single herd treatment with EPRINEX Pour-On (dosage: 0.5 mg Eprinomection/kg bodyweight) during pasture season was investigated in a dairy herd of 320 dairy cows. A further aim of thestudy was to evaluate whether such mid-summer treatment with EPRINEX Pour-On due to its endo-ectocide action would at the same time also result in a metaphylaxis of gastro-intestinal and lung worms and in a reduction of fly infestation. Due to clinicalsymptoms mange prevalence in the herd prior to treatment was 11 percent. After treatment, clinical symptoms disappeared within 2 months completely and did not re-occur during the subsequent housing period. Chorioptes mites during the entire trial periodno longer were detected. The final clinical and parasitological investigation shortly before turn-out the next year (April 1999) demonstrated chorioptes mange to be eradicated clinically and parasitologically. Due to the mid-summer treatment infestationwith gastro-intestinal helminths also was eliminated and clinical symptoms of helminth infestations during the pasture season no longer were observed. However, at housing in November, low numbers of eggs of gastrointestinal nematodes were detected in 6%of dairy cows, 32% of second-season and 63% of first-season heifers, respectively. Milk yield per cow and day on average increased by 1 litre after treatment with EPRINEX Pour-On. This increase in production is likely a result of the reduction in total parasite burden of lactating cows.