SG_USA_January_2022

WE HAVEMANY ANTHELMINTIC OPTIONS SANTA GERTRUDIS Product ion By Randy L. Stanko, Ph.D., Texas A&M University-Kingsville A ny deworming protocol for your herd is best developed with input from your ranch veterinarian. These professionals will know of

The remaining drug family, nicotinic, has been success- fully used to control parasites in cattle, small ruminants and horses. Nicknamed “clear drenches,” they are colorless and are not available as a pour-on or as injectables. However, they can also be purchased as medicated pellets (Rumatel for cattle and goats) or as an oral paste (Strongid for horses), and are broad-spectrum drugs that control all mature gastrointestinal nematodes ( Haemonchus , Ostertagia and Trichostrongylus ). Regardless of drug family you use, the three main goals of any deworming program should be to avoid development of resistant parasites, strategically deworm when necessary, and optimize money spent and drug efficacy. In small cattle herds, it may make sense to individually treat based upon general appearance (haircoat and body condition score) or fecal egg count. In larger herd systems, it is economical to treat specific production categories according to parasite risk (i.e., pre-weaning, weaned calves, replacement heifers, etc.). Management practices such as stocking rates and weather, especially rainfall, can dramatically influence cattle’s parasite loads. Some locations may not need to regularly deworm, some ranches may only need to deworm once per year (usu- ally early summer), and some more wet and humid regions must deworm twice per year (usually May-June and Novem- ber-December).

any current and local internal parasite problems as well as effective products of choice. If you are having trouble finding a specific anthelmintic product on the shelves of your local animal health supplier, it may not be due to “supply-chain disruption.” I would not get concerned, because we have sev-

eral options for deworming our cattle. Moreover, it may be a good time to switch things up on those pesky parasites. Basically, there are three different families of anthelmintic drugs: benzimidazoles, nicotinic and macrolytic lactone. The macrolytic lactone products are the most recently developed (1980-1990), and one of these may be currently in short supply. This anthelmintic family, like most others, has a wide margin of safety plus some persistent activity. This family has multiple products available with slightly different active ingre- dients, albeit from the same drug family. This family does a great job controlling Ostertagia and Haemonchus species. Products from this family are available in pour-on or inject- able options, which can vary in slaughter withdrawal times. Please read manufacturers’ labels carefully before you pur- chase, as the same product can differ in terms of withdrawal time, based on route of administration. One product in this family has no meat withdrawal time, which would be great for feedyard cattle. Due to overuse of this particular drug family (not only for deworming but also limited fly control), I would suggest you try different products within this family in a yearly rotation schedule. The oldest and probably most familiar anthelmintic family is the “white” dewormers (benzimidazoles). The individual product names mostly all end in “dazole” and have been used in multiple species of animals for many years. This particular family of anthelmintic is the most user friendly, with a medicated pellet treatment option. Due to the age and years of product use, internal parasites across the country may have some resistance to this family of drugs. However, this family does very well controlling Cooperia species of parasite. If you have been using deworming products from another family for several years, it may be time to try benz- imidazoles again because it is a broad-spectrum deworming drug family.

Photo from C Bar C Ranch, De Soto, Mo.

George West, Texas (361) 566-2244 lacampanaranch.com campana@granderiver.net

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