Developmental anomalies in farm animals: I. Theoretical considerations.

The incidence of developmental abnormalities in domestic animals is low, however there is continuing pressure on the veterinarian to answer concerns of the producer as to why the abnormality occurred and what significance it has for the rest of the herd. Generally, both normal and abnormal development are products of both genetic and environmental factors. These genetic and environmental factors can be single or multiple in nature. Interactions between environment and genes may confuse matters further. In addition, a number of genetic or environmental factors may produce the same abnormality. For these reasons, one must be aware of the complex principles of normal development and how they may be disturbed before attempting a methodological approach to solve etiology.