DISEASES OF THE RESPIRATORY PASSAGES 169 



ASTHMA 



Cause. — Asthma in fowls and canaries may be due to as- 

 pergillosis of the air passage or it may be due to other 

 catarrhal conditions of the mucous membranes of this passage. 



Sjjmpfoms. — Wheezing sounds are noted and in expiration 

 there is a creaking, whistling sound. 



Treatment. — G-ood sanitary surroundings, clean coop, no 

 draft. Treat local condition of which this is a symptom. 



ULCERATIVE PHARYNGITIS 



Symptoms. — The bird may remain on the roost mucli of 

 the time; there is an unkempt appearance of the plumage; 

 there is gradual loss in flesh when the appetite is interfr^red 

 with, and the bird may find it difficult to swallow. In eat- 

 ing corn, wheat and particularly whole unhulled oats the 

 throat is irritated and swallowing is difficult, the bird chok- 

 ing down, opening its mouth, and sometimes protruding its 

 head into the air. A coughing sound is made as the bird 

 throws its head. While on the perch or standing tucked up 

 around the yard, the bird may be noted to occasionally open 

 its mouth, and in fact sitting or standing with its mouth partly 

 open is a diagnostic symptom. 



Appearance. — When the mouth is opened and the pharynx 

 observed it will be noted to be covered, to a more or less de- 

 gree, w^ith yellowish white ulcers varying in size from a wheat 

 grain to as large as one's thumbnail. 



Microscopic. — In an examination of the sections from dis- 

 eased areas under the microscope one finds an ulceration of 

 a diphtheric nature. 



History. — This condition has been studied in many flocks 

 where roup has not appeared for years and where there were 

 no symptoms of any of the three types of roup. It is not 

 believed to be caused by the roup microorganism, but an en- 

 tirely separate disease. 



BRONCHITIS 



In some cases we have noted catarrh commencing in the 

 head, principally the nasal chambers, extend down and in- 

 volve the trachea (wind-pipe), and even to the bronchi 

 (branches of the trachea leading to the lung tissues). Sud- 

 den changes in the weather, dampness and roosting near a 

 crack in the henhouse so that a cold wind ])lows upon them, 

 or, in fact, in any draft, are the principal causes of bron- 

 chitis. 



Symptoms. — A rattling sound may be heard in the region 



