96 POULTRY DISEASES 



that recover are stunted and do not make satis- 

 factory growth. The greatest loss is from the first 

 few days to, in some cases, two or three weeks. 

 It is probahle that the carriers are chicks that have 

 recovered, but which still carry the organism (es- 

 pecially in the ovary) as the human typhoid car- 

 riers carry the germs of typhoid fever, in the in- 

 fected kidneys and in bowel ulcers. These ' ' car- 

 riers," having established an immunity, do not 

 themselves succumb to the disease, and they rarely 

 show any outward symptoms of it. 



Insanitary conditions, spoiled feed, dirty, stag- 

 nant water, improperly ventilated incubators, 

 brooders and building, or badly regulated heat, 

 are factors in weakening the physical condition 

 of chicks and favor ravages of diseases. 



Coccidian Form. — The. mode of spread of this 

 form is at present problematical. It is possible 

 that a chronic type of coccidiosis occurs in some 

 birds and thus perpetuates and diseminates the 

 protozoa. 



Postmortem Findings: Bacillary Form. — The liver in gen- 

 eral is usually pale, showing areas of congestion (active and 

 passive congestion and cloudy swelling). The yolk only par- 

 tially absorbed, congestion of the intestines may or may not 

 be present. Kidneys normal in size, but show congestion 

 and cloudy swelling. Carcass more or less pale and emaciated 

 and anemic. 



CoociAian Form. — ^Upon postmortem examination the con- 

 ditions are found to be similar to those in the bacillary form, 

 except there will be noted more or less congestion of the in- 

 testinal mucosa (lining), and ulcers in the intestines, prin- 

 cipally the ceca. The ceca appear to contain considerable 

 ingesta, and to be interfered with functionally. 



Fig. 34 shows a transverse section through an ulcerated 

 area. In these areas we find cloudy swelling, followed by 

 necrosis (retrogressive changes and death of the cells).. The 

 remains of the dead cells forms a cheesy mass (caseation 

 necrosis). It will be noted in this drawing that only rem- 

 nants of a few of the glands normally present are yet intact, 

 the remainder of the mucous membrane and in places the 



