Extension Circular 73-1907 is about internal parasites in cows and how they affect cattle production. Internal parasites continue to be one of the major problems confronting cattle producers. In 1965, the United States Department of Agriculture estimated that internal parasites in cattle caused an average annual loss of $161,678,000. The internal parasites responsible for the annual loss are listed below. Anaplasmosis. .$ 36,001,000 Coccidiosis . . . .14,569,000 Worm Parasites .100,046,000 Liver Flukes . . . 3,022,000 Trichomoniasis .. 8,040,000 In cattle the effects of internal parasites will be well camouflaged. However, additional feed will be required to reach market weight. Parasitologists have estimated that subclinical infections of ...