150 I'OII.TRY niSKASES AxND TMKIK TKKAT.M KNT. 



White Comb. 



This name is often used for faviis, but some authorities (e. g., 

 \'ale) use it to designate a condition of the comb character- 

 ized by a white powdery scurf of the surface. The comb is 

 Hght colored and the white scales or flakes are particles detached 

 from the epidermis. This condition is thought to be due to 

 anemia. Wris^ht says that it "appears generally due to dirt, or 

 overcrowding in small space, or want of green food." The 

 only treatment advised is to place the birds under sanitary con- 

 ditions and give them a good balanced ration. 



Chicken Pox (Sore Head or Epithelioma Contagiosum). 



This contagious disease of poultry, although widely distrib- 

 uted in the northern states, is less common and serious here 

 than in the Gulf States and Hawaiian Islands. It is impossible 

 al present to decide whether this is a distinct disease or a form 

 of roup which affects the skin of the head. This can only be 

 determined when further investigations have revealed the real 

 cause of these diseases. 



Diagnosis. The disease usually appears as warty nodules on 

 the un feathered parts of the head. They look like the tumors 

 in the nasal passages and eye sockets of birds affected with 

 roup. 



Freidberger and Frohner* give a good description of these 

 nodules on the skin of the head, as follows: 



"Their favorite seats are those parts of the head that are not 

 covered with feathers; root of the beak, neighborhood of the 

 nostrils, angles of the mouth, lobes of the ear, parts adjacent to 

 the auditory meatus, wattles, surface of the face, edges of the 

 eye-lids, intermaxillary space, and especially the com!). They 

 sometimes spread over the feathered parts of the head, throat* 

 and neck, and may occur on the outer surface of the thighs, 

 abdomen, under the wings and in the vicinity of the cloaca. 

 At first these cpitheliomata appear in the skin, as flat nodules, 

 which soon become prominent, and which vary in size from a 

 poppy seed to a millet seed. Later on, they usually attain the 

 size of a hemp seed. They are of a reddish-gray or yellowish- 

 gray color, often show distinctly in their earlier stages of devel- 

 opment a peculiar greasy, nacreous lustre ; and are rather firm 



*Freidberger and Frohner. Veterinary Pathology (Vol. I. Hayes 

 transO- Quoted from Cary. 



