THE COMPARATIVE FIELD EFFICACY OF 2 ANTHELMINTIC TOPICAL POUR-ON FORMULATIONS

Twenty-six naturally parasitized yearling cattle located on summer pas ture in Magnolia, Kentucky, and 433 naturally parasitized incoming fee dlot steers in Buffalo, Oklahoma, were selected for use in two separat e field efficacy studies. Animals in the first treatment group of each study received levamisole pour-on (Totalon(R) Pour-On Dewormer:Mallin ckrodt Veterinary, Inc., Mundelein, IL). The animals in the second gro up received ivermectin pour-on (Ivomec(R) Merck & Co., Inc., Rahway, N J). In the Kentucky study, (Table 1) a cross-over design was conducted where the cattle that received Ivomec Pour-on in the first trial rece ived Totalon in the second trial while the cattle that received Totalo n in the first trial received Ivomec Pour-on in the second trial. Diff erential fecal worm egg counts were conducted using the Modified Wisco nsin Sugar Flotation Technique and reported as number of eggs/3-g samp le.