Transcriber’s Notes Obvious typographical errors have been silently corrected. Variations in hyphenation and accents have been standardised but all other spelling and punctuation remains unchanged. Italics are represented thus _italic_. [Illustration: _PROFIT OR LOSS_] POULTRY DISEASES Causes Symptoms and Treatment With Notes on Post-Mortem Examinations E. J. WORTLEY, F. C. S. _Illustrated_ NEW YORK ORANGE JUDD COMPANY 1915 LONDON KEGAN PAUL, TRENCH, TRÜBNER & CO., Limited Copyright, 1915, by ORANGE JUDD COMPANY _All Rights Reserved_ Entered at Stationers’ Hall _LONDON, ENGLAND_ PRINTED IN U. S. A. PREFACE Poultry farming as a means of profit can be made successful only by maintaining the most vigorous and sustained campaign against disease. The aim of the poultry rearer should be to stamp out disease by preventive measures. Practical experience proves the inefficiency of many so-called cures, and points to the urgency of poultrymen endeavoring to understand more thoroughly the causes of the ailments to which domestic fowls are liable. My aim is to put a concise handbook into the hands of poultry rearers, who should thus be assisted in determining the various diseases and in taking the precautionary steps important in preventing the introduction and spread of contagious diseases. No effort is made to elaborate the scientific side of the subject. Those desirous of obtaining full information about the types of organisms that have been proved to be the specific causes of, or to be invariably associated with, particular disorders, may do so with profit by obtaining fuller works on the subject. Many scientific workers are devoting their time to the problem of combating diseases among poultry, and assistance is willingly given by officers of the experiment stations to farmers who desire to identify any disease causing loss in their flocks. The practical poultryman will recognize the fact that measures for the control of disease cannot be limited to sanitation and the treatment of sick birds, but, in reality, include such important matters as the selection of healthy stock, intelligent feeding, proper housing, and other details essential to the successful management of poultry. I gratefully acknowledge my indebtedness to the works of Dr. D. E. Salmon and John H. Robinson, editor of Farm Poultry, and to the recent publication on poultry diseases by Dr. Raymond Pearl, Frank M. Surface, and Maynie R. Curtis. My thanks are due to R. S. Martinez for the care taken in making the photographs from which the drawings for the illustrations in the chapter on Post-Mortem Examinations were prepared. Much valuable information has also been obtained from bulletins issued by the experiment stations of the United States and by the Ontario Agricultural College of Canada. E. J. WORTLEY. CONTENTS PAGE CHAPTER I GENERAL METHODS OF CONTROLLING DISEASE 1