Diseases of the Respiratory System 



157 



there is more fever, dullness and prostration. Harrison and 

 Streit say that although the head is often very hot the body 

 temperature is normal or only very slightly higher than nor- 

 mal. The discharge from the nasal opening is at first thin 

 and watery, but in two or three days becomes thick and ob- 

 structs the breathing. The inflammation, which begins in 



Eye displaced and closed by 

 swollen membranes. 



Fig. 



29. — Photograph of a fowl's head showing infra-orbital tumor caused 

 by roup. (After Roebuck.) 



the nasal passages, soon extends to the eyes and to the spaces 

 which exist immediately below the eyeballs. The eyelids 

 are swollen, and are closed much of the time. They may be 

 glued together by the accumulated secretion. The birds 

 sneeze and shake their heads in their efforts to free the air 

 passages from the thick mucus. The appetite is diminished 

 and the birds sit with their heads drawn in, wings drooping, 

 with the general appearance of depression and illness. 



