Current and future trends in managing internal parasites in forage based livestock

Authors: Burke, Joan

Submitted to: Animal Frontiers
Publication Type: Review Article
Publication Acceptance Date: 7/12/2024
Publication Date: 10/14/2024
Citation: Burke, J.M. 2024. Current and future trends in managing internal parasites in forage based livestock. Animal Frontiers. https://doi.org/10.1093/af/vfae022.
DOI: https://doi.org/10.1093/af/vfae022

Interpretive Summary: Due to the wide prevalence of anthelmintic resistant parasites and the desire to minimize pharmaceutical interventions for parasites in livestock, alternative control methods have been explored in ruminant livestock and interventions are needed for free range poultry and horses. Many veterinarians around the world continue to offer antiquated recommendations to their farm clients of frequent administration of dewormers, unaware of the extent of dewormer resistance or the value of alternative worm management strategies. An introduction is presented to articles that discuss these topics in a special issue on parasitism in livestock, poultry and horses.

Technical Abstract: Gastrointestinal nematodes or worm parasites in grazing livestock and horses are a major health challenge due to worldwide prevalence of the parasite’s resistance to available dewormers. Pharmaceutical companies have limited interest in development of new products because of cost and the likelihood that worms will develop resistance to new compounds and continue to market older dewormers. Small ruminants have an immediate threat of parasite infection from barber pole worm or Haemonchus contortus, a blood-sucking nematode parasite whose life cycle includes adult egg laying in the stomach or abomasum and egg hatching and larval development on pasture. Cattle nematode parasites are less pathogenic, though can lead to lower body weight gains in younger animals, and anthelmintic resistance of these parasite is a growing concern. Few cattle producers are aware of dewormer resistance. Many veterinarians around the world continue to offer antiquated recommendations to their farm clients of frequent administration of dewormers, unaware of the extent of dewormer resistance or the value of alternative worm management strategies. This is because few veterinary parasitologists exist, older veterinarians understood the value of anthelmintics and mentor their young veterinarians to give the same recommendations. And, few veterinarians are knowledgeable about small ruminants due to limited economic incentives to work with these farmers.