PREFACE. 



The literature on infection and the etiology and morbid 

 anatomy of infectious diseases of animals is exceedingly rich in 

 the results of new discoveries and important investigations. 

 However, students just beginning this study and following a 

 prescribed curriculum have not the time nor are they prepared to 

 read with profit the detailed records of original research. Such 

 publications seem to be better adapted for those doing advanced 

 or graduate work. Furthermore, many of these publications are 

 out of print and are only available for consultation. For these 

 reasons it is believed that a volume containing the rudiments 

 of the subject will be of use to the student and an aid to the 

 teacher. It is also believed that such a work will be of assistance 

 to practitioners. 



In preparing this volume the aim has been to bring to- 

 gether in a concise form the fundamental facts in the path- 

 ology of the more common infectious diseases of animals, 

 especially those existing in the United States, with which 

 sanitarians and the practitioners of comparative medicine must 

 contend. To this end, the current literature, the reports of 

 the investigations made at various Institutions and Experi- 

 ment Stations, as well as the standard works on comparative 

 pathology have been freely drawn upon and to all of w^hich 

 full acknowdedgment is hereby made. 



In order to bring into consideration the clinical value of a 

 knowledge of morbid anatomy, a few of the symptoms or ante- 

 mortem manifestations have been included. It is hoped that 

 this correlation of symptoms and lesions will stimulate a deeper 



