This book has been written in the hope that it will be of assistance to veterinary students, veterinary practitioners, and others con cerned with the well-being of animals. The requirements of those studying for the Diploma of Veterinary State Medicine have been kept in mind, and special attention has been given to certain branches of Public Health work with which they should be conversant. Other sections of veterinary science which might have been included, such as Dietetics, Zootechny and Milk Hygiene, have been omitted, as their importance merits a more detailed consideration than could be accorded in one volume. It is anticipated that they will later form additions to the Series.