The fact that animal parasites are important as disease producing agents has been known for a great many years. Thought, consideration, study, and emphasis on the question of parasitism have come in waves; at times it was looked upon as one of the most important factors to be dealt with, while at other times or periods it has received almost no attention and parasites have been looked upon as more or less unimportant as disease producing agents. But the necessity for the protection of our livestock from disease has grown, being governed largely by the supply and demand, together with the rearing of animals under more or less intensive conditions, the modern commercial method of handling animals for food purposes, the very general interchange of breeding stock, the numerous stock shows, and other conditions that make possible the spread of parasitic diseases. Further, it has been proven that many parasites are carriers, directly or indirectly, of the causes of specific diseases and thus parasites as well as all classes of disease-producing agents have of necessity received attention.
Proceedings of the Iowa Academy of Science
©1921 Iowa Academy of Science, Inc.
Werner, Herbert R.
"Methods of Teaching Parasitology,"
Proceedings of the Iowa Academy of Science, 28(1), 215-221.
Available at: https://scholarworks.uni.edu/pias/vol28/iss1/37