lOG Diseases of Ponlfrj/ 



from a few hours to a day or two. Or it may be subacute, in 

 which case the bird Hngers for several days. Likewise 

 within the flock the birds may die rapidly until the majority 

 of the flock are gone within a few days or they may die a few 

 at a time throughout a period of several weeks. The period 

 of incubation, i.e., from the time of exposure until the first 

 symptoms, varies from 1 to 2 days in geese and from 4 to 

 9 days in chickens.^ Salmon states that the incubation 

 period may be as much as 20 days. 



Examination of the dead birds shows inflammation of 

 the digestive organs, kidneys, and mesenteries in nearly all 

 cases. Accordmg to Ward "" " punctiform hemorrhages are 

 found upon the heart with almost absolute uniformity. 

 The liver is very frecjuently marked with punctiform 

 whitish areas." Sections show that the areas of necrotic 

 tissue are present throughtout the liver tissue. The blood 

 vessels of the liver are congested. According to Ward the 

 next most striking lesions are found in the reddened and 

 bleeding mucosa of the first and second folds of the small in- 

 testine (next to the gizzard). These reddened areas can even 

 be seen from the outside of the intestine. The intestinal con- 

 tents are either a cream colored pasty mass or may be brown- 

 ish or even green in color. "Lesions are very rarely observed 

 in other portions of the intestine. The ureters are noticeable 

 in practically all cases by reason of the yellow-colored urates 

 that they contain. The nasal cavity, pharynx and oral 

 cavity frequently contain a viscous mucous fluid, probably 

 regurgitated from the crop." 



Mode of Transmission. — The manner in which this disease 

 gains admission to an apparently healthy flock is often a puz- 



1 Ostertag, R., uiid Ackermann, P., "Zeitsehr. Infektkr. u. Hyg. 

 Haustr." Bd. 1, pp. 431-441, 1906. 



•' Ward, A. R., "Fowl Cholera." Cal. Agr. Expt. Sta. Bui. 156, 

 PI). 3-20, 1904. 



