194 iviri/rm I)1Si:asi:s and 'iiiI'IK i'ki'.at.mivNT. 



Pia(/nosis. This disease is characterized by a (hinii)ish sleepv 

 C(>ii(htii)n of the cliick. 'J'he witigs are ])en(hilent. IJreathing 

 is rapid and sometimes accompanied by snoring sounils. A 

 whitish (harrhca is present. A (Hfferential tHagnosis between 

 thi> and the coccicHal wliite (harrliea is onlv possil)le liv an ex- 

 amination of the dead birds. In asi)ergillosis. yellowish tnl)er- 

 cle.s which closely resemble those of tuberculosis occur in the 

 lungs and in the walls of the air sacs and often also in tlie intes- 

 tines, mesentery, liver and other organs. In very acute cases 

 the lungs are simply inflamed, death occurring before the forma- 

 tion of the tubercles. The mycelium and spores of the fungus 

 may be found by microscopic examination of the tubercles and 

 this fungus may be obtained by inoculating cultures from these 

 tubercles. 



Etiology. The disease is caused by the spores of an Asper- 

 gillus usually A. fmuigatus, fig. 22. This is a very common 

 fungus and the spores are widely distributed in nature. The 

 spores are often found on the food or on the litter and are 

 inhaled or taken in with the food. Incubator chickens are 

 often infected from the incubators and brooders and hen hatched 

 chickens from the straw or chaff in the nests. Sometimes the 

 chicks get the disease from chick food not properly cared for. 

 It is possible that this disease as well as the coccidial and Ijacil- 

 lary white diarrhea is sometimes carried in the egg. The spores 

 and mycelium are often found in the digestive tract of hens 

 and it is not unlikely that they may work up the oviduct from 

 the cloaca and infect an egg before it gets its shell. 



Treatment. The treatment of diseased chicks is useless. 

 When they are infected the spores develop on the membranes 

 and new spores are formed which spread the infection through- 

 out the respiratory system and also to the other organs. The 

 only effective treatment is prevention. Keeping the flock under 

 good hygienic conditions with clean food, litter and nesting ma- 

 terial reduces the chance of infection and keeps the chicks in a 

 vigorous condition in which they are able to resist the disease. 

 The dead chicks should be burned or buried. 



Prognosis. The disease is fatal so far as known. 



Emphysema. 



This name is applied by Robinson to a disease of young chicks 

 in which the skin puffs out in the sides of the neck near its 



