Anchor Veterinary Handbook. 1984 Yearbook of Agriculture. Farm Animal Health and Disease Control. Lea and Febiger, Philadelphia. Box 187 Gladstone, Oregon 97027.
Parasite infections develop slowly and are difficult to eradicate completely.
Animals do not develop immunity, to parasites, although some resistance is apparent between age groups. Some animals do not show many symptoms, others may show symptoms such as dull hair coat, lethargic behavior, and loss of weight. Provide the students with reference texts or articles and have them make up charts of common parasites' life cycles. Post them when they are completed. There are also non-infectious agents that cause disease.