Clinical disease is often only the tip of the iceberg in a parasitic infection as the effects on the host are not readily seen on examination. Sub-clinical disease is often only seen as a decrease in productivity of the animal, for example, reduced weight gain, reduced milk yield and decreased quality of milk, hide or wool. | Clinical disease is often only the tip of the iceberg in a parasitic infection as the effects on the host are not readily seen on examination. Sub-clinical disease is often only seen as a decrease in productivity of the animal, for example, reduced weight gain, reduced milk yield and decreased quality of milk, hide or wool. |