no 



POULTRY DISEASES AND THEIR TREATMENT. 



air passages. V/hen the bird begins to improve, give a grain 

 of quinine, or lo drops of cod liver oil twice a day.' (Sal- 

 mon.)" 



Tuberculosis. 



This disease in birds does not usually affect the respiratory 

 system, but is more commonty confined to the abdominal vis- 

 cera, and is discussed with the diseases of the organs of ali- 

 mentary tract (Chap. V). 



The Air-Sac Mite. 



A species of mite (Cytodites nudiis) infects the air-sacs and 

 bronchi of poultry. 



Diagnosis. — When the birds are not badly infested there are 

 no external symptoms. If badly infested the bird may become 

 ansemic and listless and finally die of exhaustion. Or, if the air 

 passages are seriously obstructed by the collection of parasites 

 and mucus there will be a rattling in the throat and coughing, 

 and death may result from suffocation. The presence of the 

 parasites is often found only on examination of dead birds. 

 They appear as a yellow or white dust, each particle of which 

 is a mite. If closely watched the particles may be seen to move. 



Etiology. — The mite probably 

 enters the air-sacs by crawling 

 in the nostrils and finding its 

 way down the trachea and bron- 

 chi to the sacs. The parasites 

 are able to live only a short time 

 outside the bird's body. The 

 mouth parts of these mites are 

 modified into sucking tubes. 

 They attack the mucous mem- 

 brane of the air-sacs and bron- 

 chi. When the number of para- 

 sites is small they cause no seri- 

 ous inconvenience to the bird. 

 When there are a large number 

 present they may cause inflammation of the membrane and secre- 

 tion of mucus or they may seriously obstruct the air passages. 



Treatment. — Treatment of infested birds is probably useless. 

 Feeding sulphur with the food or compelling the birds to inhale 



Fi 



23. Cytodites nudus. The 

 air sac mite. Greatly enlarged. 

 (After Theobald). 



