Hematotoxicology is the study of adverse effects of drugs, nontherapeutic chemicals, and other agents in the environment on blood and blood forming tissues such as bone marrow. Assessment of blood and bone marrow in veterinary toxicology is important because chemicals and drugs can significantly affect the cellular and humoral components of the blood. The hematopoietic system is unique and serves as a cornerstone to one's understanding of the toxicology of blood and bone marrow. Hematopoietic cells are the most dynamic, proliferative, and mitotically active cells in an animal. As well as illustrating some toxicant-induced changes, this chapter is intended to provide a basic introduction to blood and bone marrow. Information provided in this chapter may serve as an important and accessible tool for understanding the basic concepts, and for monitoring and characterizing toxic responses of the blood and bone marrow. In conclusion, it is possible for a toxicologist to systematically evaluate blood and bone marrow toxicity in laboratory settings and to devise a hypothesis for the development of such toxicity. Because of this, it is imperative for toxicologists to understand the basic concepts of the hematopoietic system to interpret the results of toxicological studies. 2007 Elsevier Ltd. All rights reserved.
