Chicken Cholera. Fowl Cholera. Chicken Typhoid, etc, 163 



endocardium are usually studded with dark petechiae. and con- 

 gestion and even slight exudation may be present. The spleen 

 is enlarged, soft, and gorged with blood. The liver is swollen, 

 congested, extremely friable, and mottled, grayish white from 

 degenerations. The kidneys are dark red, and friable. The 

 lungs may show slight hyperaemia only, or a blood engorge- 

 ment and consolidation, and are then easily reduced to a dark red 

 pulp. Friedberger and Frohner say that respiratory changes are 

 most frequent in land birds ; and intestinal and cardiac in water 

 fowl. 



The blood is diffluent coagulating loosely if at all, of a brownish 

 red color, reddening slowly and imperfectly in contact with air, 

 and like the tissues contains an abundance of the characteristic 

 bacterium staining deeply at the poles and clear in the center. 



In birds that survive a few days there are marked anaemia and 

 emaciation, and the muscular system is of a grayish red color, with 

 fatty degeneration. In acute and fulminant cases on the other 

 hand the muscles may be full and of the normal red color. 



In arthritic cases the congestion and thickening of the soft 

 tissues, and the excess of synovia, are supplemented by destruc- 

 tion of the articular cartilage and by areas of bone abrasion. In 

 the more tardy cases collections of caseous matter are found. 



Diagnosis. This is based on the demonstrably highly conta- 

 gious character of the disease, its rapid spread in a flock, and 

 from the first to nearby adjoining flocks in summer, the short 

 period of incubation, the constancy and nature of the diarrhoea, 

 the speedy and great mortality, and the hemorrhagic lesions of 

 comb, bowels, heart, lungs, liver, kidneys, spleen, and serous 

 membranes. The demonstration of the bacterium in the blood 

 and affected tissues is conclusive. Kitt points out that inocula- 

 tion of a pigeon kills the bird in 12 to 48 hours, with dry yellow 

 exudate in patches of from yi to y± inch in diameter on the sur- 

 face of the muscles, and yellow discoloration and nodular indura- 

 tion beneath. 



Prognosis. The mortality reaches 90 to 95 per cent. The 

 negative chemiotaxis exerted on the leucocytes by the microbe, 

 precludes defensive phagocytosis, and the progress of the deadly 

 microbe is comparatively unhindered. Toward the end of a 

 severe outbreak, and in certain mild epizootics the recoveries are 

 much greater. 



