PRELIMINARY NOTE ON THE ADMINISTRATION OF NON-CONDITIONED PHENOTHIAZINE, IN SMALL DAILY DOSES, FOR THE CONTROL OF GASTROINTESTINAL PARASITES OF CATTLE IN PUERTO RICO

Abstract

The results of the foregoing experiments show that daily doses of 1/2 gram of nonconditioned phenothiazine per 100 pounds of live weight administered to cattle infected with gastrointestinal parasites reduced the number of worm eggs passed unto the pasture by the infected animals. The eggs of the stomach worms, Haemonchus contortus and H. similis, the small intestinal hair-worms, Trichostrongylus spp., the hookworm, Bunostomum phlebotomum, and the nodular worm, Oesophagostomum radiatum disappear relatively quickly from the feces of the treated animals. The eggs of Cooperia spp., Strongyloides papillosus, and the broad tapeworms, Moniezia spp., were not markedly reduced in number by this treatment. These results confirm those of Porter, Simms, and Cauthen (1941) showing that phenothiazine has little effect on the last three parasites mentioned. The dose rate used in these experiments compares favorably with that suggested by Shorb and Habermann (loc. cit.) for the prevention of the development of nematode larvae in the feces of sheep.