Dr. Murai Éva szerk.: Parasitologia Hungarica 22. (Budapest, 1989)

Method for evaluating the larvicidal efficacy of Strongid Plus (Pfizer) and Eqvalan (MSD) paste against gasterophilosis

4 Dr. Borisz EGRI Department of Animal Physiology and Animal Health, Faculty of Agricultural Sciences, Mosonmagyaróvár, University of Agricultural Sciences, Keszthely, Hungary "Method for evaluating the larvicidal efficacy of Strongid Plus (Pfizer) and Eqvalan (MSD) paste against gasterophilosis" - Egri, B. - Parasit, hung., 22_: 109-114. 1989. ABSTRACT. A total of 280 Nonius, Hungarian half-blood and Gidran sports stud horses were examined. In the three experimental studs, the severity of infection by Gasterophilus larvae was unknown, but the numbers of G. intesti nalis eggs in the different studs were known from the author's previous observations. Some experimental animals were treated with Strongid Plus paste (Pfizer) at a dose of 1 ml/10 kg body mass, the others with Eqvalan paste (MSD) at a dose of 0.2 mg/kg body mass. After treatment, 7166 spontaneously excreted faecal samples were examined for the presence of larvae at 2-hour intervals for 3 days. For comparative evaluation of the larvicidal effectiveness of the preparations the author calculated the relative frequency value of botfly larvae exretion, applied column diagrams and used the method of multiple regression analysis. The drugs resulted In the excretion of a total of 5623 Gaste rophilus larvae. The species distribution of larvae was: G.intestinalis 98.26%, G. pecorum 1.74%. After treatment with Strongid Plus the most expressed larval excretion occurred between the 28th and 52nd h, and with Eqvalan paste between the 50th and 64th hours. KEYWORDS: Evaluation, Strongid Plus (Pfizer), Eqvalan (MSD), gasterophilosis, sports studs. This paper reports the results of experiments with anthelmintic and boticide pastes against horse botfly larvae. These drugs had not been compared in Hungary before. The Incidence of horse botfly Infection in sports horse studs in Hungary is not sufficiently known. According to our earlier examinations the most common species was Gasterophi

lus intestinalis (de Geer, 1776> (2, 3, 4). The author examined the egg-laying activity of the parasite In sport studs during the summer of 1984 and 1985. In these periods there were no medicaments for common use against horse botfly larva. The trade of "Gastin" in Hungary had been stopped earlier. • Based on a paper presented at the Fifth European Multicolloquium of Parasitology, 4-9 September, 1988, Budapest, Hungary.