Eradication of chorioptes bovis mange in a dairy herd with turnout to graze by Eprinex Pour-On

The possibility to control or even eradicate chorioptes mange by a single h erd treatment with EPRINEX Pour-On (dosage: 0.5 mg Eprinomection/kg bodywei ght) during pasture season was investigated in a dairy herd of 320 dairy co ws. A further aim of the study was to evaluate whether such mid-summer trea tment with EPRINEX Pour-On due to its endo-ectocide action would at the sam e time also result in a metaphylaxis of gastro-intestinal and lung worms an d in a reduction of fly infestation. Due to clinical symptoms mange prevalence in the herd prior to treatment wa s 11 percent. After treatment, clinical symptoms disappeared within 2 month s completely and did not re-occur during the subsequent housing period. Cho rioptes mites during the entire trial period no longer were detected. The f inal clinical and parasitological investigation shortly before turn-out the next year (April 1999) demonstrated chorioptes mange to be eradicated clin ically 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, respectiv ely. 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.