The changing landscape of parasite control in small ruminants

What practitioners need to know

Abstract

Control of gastrointestinal (GIN) parasites is of primary concern in any small ruminant health management program, and is critical to profitability of the farm. For many years, GIN were controlled by the frequent use of anthelmintics, and this approach was quite effective. However, we now know that this strategy is shortsighted and unsustainable. Anthelmintic resistance is bounding out of control, and many of the drugs relied upon for decades no longer are effective on many farms. Furthermore, despite the occasional development of new anthelmintic classes, history clearly demonstrates that the development of resistance is almost certain to outpace the introduction of new drug classes. Thus, anthelmintics can no longer be viewed as inexpensive management tools, but instead must be viewed as extremely valuable and limited resources. Furthermore, parasite control must no longer be equated with a deworming program. Rather, parasite control will only be sustainable if it is approached as an integrated parasite management program, where anthelmintics are only 1 of several components. Additionally, there are new strategies for how we need to use our anthelmintics, the most important of which are that treatment is given selectively to animals based on need, and multiple anthelmintics are administered as a combination treatment.