18 DISEASES OF POULTRY. 



These are by, far the most common causes of disease 

 with the domesticated birds. There are other causes, 

 such as rupture of a blood vessel from weakness of its 

 walls; the degeneration of the tissues of important 

 organs through some obscure influence ; the inexplic - 

 able failure of some part of the body to perform its 

 functions and the development of abnormal growths. 

 These are more commonly observed, however, in old 

 birds, and, as financial considerations lead to the fre- 

 quent renewal of the poultryman's stock, such forms of 

 disease rarely occur and are confined to a very few birds. 



HYGIENIC REQUIREMENTS. 



The conditions required for the maintenance of health 

 and vigor in a flock of birds, are similar to what are 

 required for other animals. These conditions, how- 

 ever, are more important with birds than with quadru- 

 peds because the activities of the former are more 

 intense. That is to say the bird digests more food in 

 proportion to its weight, it breathes more rapidly, its 

 blood circulates faster, its temperature is higher, and it 

 makes a proportionate increase in weight in a shorter 

 time. The bird may, therefore, be compared to a very 

 perfect and delicate machine running under a high 

 pressure. If properly managed, such a machine gives 

 the very best results ; but if neglected and run under 

 improper conditions, it soon fails to be satisfactory 

 and may entirely collapse. 



One of the first problems which the poultryman is 

 called upon to solve is the location of the poultry plant. 

 There are some general principles which are of great 

 assistance in considering this question. The building 

 or buildings should be upon an elevated spot where 

 the drainage is good, and any danger of water settling 



