This encyclopaedic dictionary offers practical help and reference material for veterinary purposes. Entries define and describe bacteria, viruses, carriers and diseases; they offer causes, diagnoses, signs and treatment, pointing out variations in the nature of a disease when it occurs in different animals, and taking account of international scientific research observations and findings. The dictionary has been extensively revised and many entries have been rewritten since the 18th edition to reflect the numerous changes in legislation and in veterinary practice, advances in medicine and treatment, and patterns in animal husbandry and pet ownership.