The Coccidiostatic Action of Nitrophenide on Eimeria tenella

Abstract

Waletzky, Hughes, and Brandt (1949) reported that the continuous feeding of nitrophenide in the mash at a concentration of 0.05 per cent for eight to ten days, starting on the day of inoculation or one or two days before inoculation, checked mortality from severe cecal coccidiosis in chicks. They also referred to unpublished data by themselves which indicated that nitrophenide was effective in controlling Eimeria tenella infections when administered 48 to 96 hours after inoculation; the drug was ineffective, however, when administered at time of inoculation to 48 hours after inoculation. In the same paper they presented preliminary evidence to show that nitrophenide is also effective against Eimeria necatrix. Bottorff (1950) presented data from field tests to show that the feeding of nitrophenide in the mash to chicks, from one day of age through 11 weeks, reduced mortality from cecal coccidiosis. Seeger (1950) fed nitrophenide continuously in the mash at concentrations of 0.0125 and 0.00625 per cent and reported good results. Swales (1950) fed nitrophenide continuously in the mash at 0.0125 per cent concentration, starting 24 hours before exposure to contaminated litter, and obtained little protection from cecal coccidiosis. In continuous feeding at 0.05 per cent concentration, starting at time of exposure, he got widely varying results. However, he found that the feeding of 0.1 per cent concentration for four days, starting 48 hours after exposure, resulted in a definite reduction in mortality. In a more recent paper (1951), Swales reported a reduction in mortality among birds on field tests, treated continuously with 0.0125 per cent nitrophenide mash. Peterson and Hymas (1950) found that a concentration of 0.05 per cent was necessary to suppress mortality in experimental Eimeria necatrix infection. Brackett and Bliznick (1949) reported that chicks given nitrophenide continuously for the duration of the experiment discharged fewer oocysts of Eimeria tenella than did untreated chicks, and that the percentage of sporulation of the oocysts passed by treated birds was much lower than that of the oocysts passed by untreated birds. Dickinson, Babcock, and Osebold (1951) found that continuous feeding of nitrophenide in the mash at a level of 0.05 per cent suppressed oocyst development of both cecal and intestinal coccidia, and gave protection from the disease during the period of administration of the drug.