How to test nontarget effects of veterinary pharmaceutical residues in livestock dung in the field

Abstract

To register veterinary medicinal products (VMPs) as parasiticides on pastured animals, legislation in the European Union requires an environmental risk assessment to test the potential nontarget effects of fecal residues on dung-dwelling organisms. Products with adverse effects in single-species laboratory tests require further, higher-tier testing to assess the extent of these effects on entire communities of dung-dwelling organisms under more realistic field or semifield conditions. Currently, there are no documents specifically written to assist researchers in conducting higher-tier tests or to assist regulators in interpreting the results of such tests in an appropriate context. Here we provide such a document, written by members of the SETAC Advisory Group DOTTS (Dung Organism Toxicity Testing Standardization) with research experience on dung fauna in central and southern Europe, Canada, Australia, and South Africa. This document briefly reviews the organisms that make up the dung community and their role in dung degradation, identifies key considerations in the design and interpretation of experimental studies, and makes recommendations on how to proceed.

A Review on the Toxicity and Non-Target Effects of Macrocyclic Lactones in Terrestrial and Aquatic Environments

“…However, with the exception of IVM and, to a lesser extent, MOX and DOR, the knowledge available from the open literature is still very limited. The immediate challenge therefore is to devise ways of filling the gaps in our knowledge base, focusing in particular on: The refinement and expansion of our understanding of pharmacokinetics and toxicology in order to provide a better basis for environmental risk assessment of MLs [325];Performance of tests on different levels (laboratory, semi-field and field) following standard test guidelines whenever possible (for coprophilous arthropods see, for example, OECD 2008 and OECD 2009) [52-53]; Performance of higher-tier studies under realistic (field) conditions, including structural (biodiversity) and functional (dung decomposition) endpoints (see for example Jochmann et al ) [326];Definition of the goals to be protected when assessing the potential environmental risks of new MLs and / or new formulations;Linking ecological knowledge ( e.g. population dynamics of single species) with ecotoxicological risk assessment, with a long-term aim of modelling the impact of these compounds on ecosystems in the field, particularly at the landscape level.…”

“…Performance of higher-tier studies under realistic (field) conditions, including structural (biodiversity) and functional (dung decomposition) endpoints (see for example Jochmann et al ) [326];…”

Ivermectin sensitivity is an ancient trait affecting all ecdysozoa but shows phylogenetic clustering among sepsid flies

“…; Jochmann et al. ), thus extending the registration process already required for these drugs (VICH ). In this context, the issue of regionalization of substance control should also be considered, as is already being discussed (EFSA ).…”

Implications of Endectocide Residues on the Survival of Aphodiine Dung Beetles: A Meta‐Analysis

“…Our results indicate a significant overall negative effect of endectocide fecal residues on the abundance of both larval and adult aphodiine beetles. The high heterogeneity (I 2 ) associated with study-specific factors (e.g., time of year, temperature, species, endectocide product, formulation) confirm the value of developing a standardized procedure for tier B testing (Jochmann et al 2011).…”

“…In addition, endectocides include both avermectins (e.g., doramectin, eprinomectin, ivermectin) and milbemycins (e.g., moxidectin) that can be formulated and administered to livestock as oral pastes, injections, extended‐release injections, pour‐ons, and sustained‐release boluses (Herd et al 1996). All of these factors influence fecal concentrations of endectocide residues entering the environment (Lumaret et al 2012) and the interpretation of results (Jochmann et al 2011). Relatively few studies have directly compared the nontarget effects of different endectocides (Hempel et al 2006; Webb et al 2010) or of the same endectocide in different formulations (Herd et al 1996).…”