Eradication of Chorioptes bovis mange in a dairy herd with turn-out to graze by Eprinex Pour-On

The possibility to control or even eradicate chorioptes manage 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 the study 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 clinical symptoms manage 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 period no 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 infestation with gastrointestinal 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.