EPITHELIOSIS INFECTIOSA AVIUM 597 



Mouth.— Involvement of the mucous membrane of the 

 mouth begins as a local disturbance. The disease is ushered 

 in by a slight redness or congestion of isolated areas, or 

 may involve the entire surface. In the center of the con- 

 gested areas there will appear in a day or so small round 

 or oval yellowish -white spots, which rapidly spread and 

 eventually form extensive collections of glutinous pus, 

 having somewhat the appearance of diphtheritic mem- 

 brane. The nature of the collected material on these areas 

 led to the name "diphtheria" for this form. As the disease 

 progresses this process often extends over the entire mucosa 

 of the mouth, tongue and throat. When the larynx is 

 involved, or even the trachea, as is occasionally noted, there 

 will be marked symptoms of dyspnea. Asphyxia is fre- 

 quent when the lesions extend to the larynx and trachea. 

 On removal of the deposits the mucosa presents a red, 

 granulating surface, which bleeds easily, showing in some 

 cases extensive submucous swelling and edema. The com- 

 missures of the mouth are frequently involved as is the 

 skin and contiguous tissues, a characteristic pox lesion 

 developing in the skin. Other complications are frequently 

 found spreading from the oral cavity, i. e., to the pharynx, 

 esophagus and crop, producing severe diarrhea and other 

 bowel disturbances. 



Skin.— Lesions on the skin are found in quite a few cases, 

 more commonly on the comb, wattles and other portions 

 of the skin not covered with feathers. It is first noticed 

 as a very fine gray vesicle, which soon develops into small 

 elevations of a reddish-gray color, which later become more 

 grayish. Microscopically the nodules are composed of 

 degenerated epithelial cells. These nodules in some cases 

 become quite large, warty in appearance, dry and hard. 

 In severe cases large numbers of these nodules are found 

 distributed over the skin on exposed surfaces. On removing 

 the surface of the nodules a raw granulating area is noted. 

 Some cases show distinct degeneration of contiguous tissues. 



A mixed variety of the disease is of frequent occurrence, 

 the mucosa showing the characteristic deposits and the 

 skin pox lesions. It is quite evident in these cases that 



