Immunotoxicity in the bovine animal: a review.
The immune system is a complex biological system involving cellular defenses as well as endogenous and exogenous factors. The potential for immune system exposure to immunotoxins in the environment is well documented. However, caution should be exercised when extrapolating meaningful conclusions from experimental data to assess risk factors to the bovine. Mycotoxins alter immune-mediated activities in cattle and are major immunotoxic risks. Another risk to the bovine is lead. Poor disposal of pollutants in the environment enhances this risk factor. One of the most controllable risk factors is the administration of immunotoxic drugs and biologics. Most of these compounds have minimal immunotoxic activity at recommended dosages. The extra-label use of drugs resulting in super-therapeutic concentrations has increased the probability that certain drugs may act immunotoxicologically.