Abstract
Experiments involving cattle, horses, pigs and fowls are presented which are considered to give evidence that thiabendazole is highly active against the Strongyle parasites but not so active against the ascarid parasites of the digestive tract of these animals. The strongyles of cattle can be controlled with a dose of 75–100 mg./kg. and those of horses with as little as 25 mg./kg. In pigs 100 mg./kg. was very active against Oesophagostomum dentatum but this dose level was of poor efficiency against Ascaris lumbricoides. A high dose of 500 mg./kg. appeared to be necessary to control Ascaridia galli in the fowl.