Inventory of the use of antiparasitic drugs in dairy cattle in the Netherlands

Abstract

Antiparasitic drugs exist to reduce the negative effects of parasitic infections. The use of these drugs has negative side effects, such as the risk of antiparasitic drug resistance and negative effects on the environment. To estimate the extent of these effects, it is necessary to know how often and which antiparasitic drugs are administered. This is the first study to quantify the use of antiparasitic drugs in dairy cattle in the Netherlands. This is done by translating the sales data of the Universitaire Landbouwhuisdieren Praktijk (ULP) into defined daily dosages per animal (DDDA). A total of 273 farms is included in this study. To evaluate the antiparasitic drug use on farm level, the DDDAF was calculated. For drugs authorized for specific age categories, the DDDAS was calculated, using the number and weight of the corresponding age categories. Two different DDDAS were calculated, the DDDAS ‘Cattle aged <2’ and the DDDAS ‘Cattle aged <1’. The seasonal distribution was made visible by showing the DDDA values per quarter. An indication of a seasonal effect in the use of antiparasitic drugs was found, however, to confirm this effect, it should be studied more extensively. The DDDA values of the population show a wide spread, on farm level as well as in the specific categories. A large part of the population does not even use antiparasitic drugs at all. The wide spread together with the number of no use farms indicates that an overall reduction is possible a reduction with the goal of preserving the ability to treat infected animals and minimize the effects for the environment.