Quantitative Monitoring of Selected Groups of Parasites in Domestic Ruminants: A Comparative Review

Parasites have had a significant impact on domestic ruminant health and production for a long time, but the emerging threat of drug resistance urgently requires an improved approach to parasite monitoring and control activities. The study reviewed the international literature to analyze the different proposals for the sampling approach and the quantitative estimation of parasite burdens in groups of animals. Moreover, the use of thresholds to decide when and which animal to treat was also investigated. The findings of the study highlighted the presence of a wide-ranging literature on quantitative monitoring for gastrointestinal nematodes (GIN), while more limited data were found for coccidia, and no specific indications were reported for tapeworms. Concerning liver flukes, bronchopulmonary nematodes (BPN) and permanent ectoparasites (lice and mange mites), the diagnostic process is usually aimed at the detection of the parasite rather than at the burden estimation. The main research gaps that need further investigation were also highlighted. For some groups of parasites (e.g., GIN and coccidia) the quantitative approach requires an improved standardization, while its usefulness needs to be confirmed for others (e.g., BPN and lice). The development of practical guidelines for monitoring is also encouraged.

Automated summary

The study reviewed international literature on quantitative monitoring of parasites in domestic ruminants and found a wide range of information for gastrointestinal nematodes (GIN), limited data for coccidia, and no specific indications for tapeworms. For parasites like liver flukes, bronchopulmonary nematodes (BPN), and ectoparasites, the diagnostic process mainly focuses on parasite detection rather than burden estimation. Research gaps were identified, particularly in the standardization of quantitative approaches for certain parasites and the need for further investigation into the usefulness of monitoring guidelines.