PREFACE .TO THE FIRST EDITION 
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. Further- 
more, many of these publications are out of print and are only avail- 
able 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 together in a 
concise form the fundamental facts in the pathology of the more 
common infectious diseases of animals, especially those existing in the 
United States, with which sanitarians and the practitioners of com- 
parative medicine must contend. To this end the current literature, 
the reports of the investigations made at various institutions and 
experiment stations, as well as the standard works on comparative 
pathology have been freely drawn upon, to all of which full acknowl- 
edgment is hereby made. 
In order to bring into consideration the clinical value of a knowl- 
edge of morbid anatomy a few of the symptoms or antemortem 
manifestations have been included. It is hoped that this correlation 
of symptoms and lesions will stimulate a deeper interest in the study 
of comparative pathology and thus render it of more permanent and 
practical value for those entering into the practice of veterinary 
medicine. 
In selecting the subject matter care has been taken to avoid, as 
far as possible, the introduction of results concerning which there are 
controversies. It has seemed best to deal with those facts about 
which at the present time there is little or no doubt. After the 
discussion of each disease a few references to the literature are ap- 
pended. These are intended simply to bring the attention of the 
student to afew publications respecting the cause and morbid anat- 
omy, considered in the light of modern etiology, of the disease in 
question and to a few articles containing the results of original research. 
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