Diagnosis and management of bovine chemical toxicoses

[Bovine Toxicology]

Abstract

Many bovine toxicologic problems considered in the past have been acutely fatal or disabling syndromes. They have been hard to ignore when they occur. Thus acute arsenic poisoning, insecticide induced seizures, and herd outbreaks of nitrate or cyanide poisoning have been well-known examples of problems for veterinary toxicology. Problems like these still exist and may cause devastating losses for individual producers. However, these problems are, for the clinician, generally easily recognized and there are sound recommendations for their control. With the introduction of more complex and numerous chemicals in agriculture and industry as well as changing procedures in livestock production, the classical veterinary poisons are no longer sufficient subject matter for livestock health professionals. Clinical problems induced by newer chemicals may be vague and hard to difine. Death may be less important than an economic effect such as poor performance or increased susceptibility to infectious disease after exposure to toxicants. Presence of illegal residues either from improper use of approved drugs or inadvertent exposure to chemicals continues to be of concern to practitioners, producers and regulators. This paper will deal, not in the entire range of bovine toxicology, but with well- known examples of toxicants which are still real~or potential problems. Some are highly toxic, others are cumulative and cause residues. The reader is urged to consult one or more of the supplemental readings for more complete discussions of classical toxicologic problems.
The situations to be discussed are as follows: 1) those problems arising when animals are contacted by chemical products or by-products of industry or commerce 2) toxicologic effects and residues associated with use (misuse) of pesticides or economic poisons, and 3) toxicosis or loss from exposure to metallic poisons.