I^J I'oii.iin' DISIvASKS AND TlIi:iK TKKAT M KNT. 



The- prc'scncf of these nodules on the epithelium of the lu;i<l 

 is often (l)ut apparently not always) accompanied with cliar- 

 acteristic roup lesions of the nasal cavities, mouth and throat. 

 As lon«r as the disease is confined to the skin of the head the 

 fjeneral health of the bird does not seem U> l)e affected. Recov- 

 ery mav take place without treatment in from lO to 20 days. 

 The nodules in such cases dry up and fall olf. Usually, how- 

 ever, the disease is not self-limited, but advances. The eyes 

 may become closed so that the l)irds cannot see to eat. They j^et 

 poor and die from exhaustion. When the mucous membrane 

 of the mouth developes diphtheritic membranes death occurs 

 earlier than in other forms. 



pJioloi!;y. The lesions of this disease resemble the lesions of 

 roup and many of the same micro-organisms are found in the 

 two cases. The organisms isolated from tlie lesions of sore- 

 head include several bacteria, a coccidium, a yeast and several 

 moulds. The coccidium, one of tlie moulds, and one of the 

 bacteria have each been considered tlie cause of the di.sease by 

 different workers. The real cause of the disease and its rela- 

 tion to roup must be determined by further investigations. The 

 following discussion of the etiology of sore-head is given by 

 Gary (Chicken-Pox or Sore Head in T^oultry. Alabama Agric. 

 E.xpt. Stat. P.ulletin 136) : 



"Tnuismissiou and Dissemination. It is evidently infec- 

 tious; becau.se the disease in all its forms, spreads rather rai)idl\- 

 from one chicken or pigeon to another. Ward, Harrison and 

 others have transmitted, in some cases (|uite readily by carrying 

 small amount of di.seased material (exudate and blood), from a 

 .sore-head chicken to healthy chickens. It is also quite certain 

 that chicken pox and pigeon pox are identical or one and the 

 same disease." 



"Mosquitoes, gnat flies, chicken mites (ticks), chicken lice, 

 chicken foot mites {Sarcoptcs miitans) and possibly cock-roaches 

 may .sometimes be carriers of the real virus. It seems quite cer- 

 tain that mosquitoes can transmit the virus from water or some 

 other source, under certain conditions. Warm and wet weather 

 seem to increase the virulency of the virus and favor the rapid 

 transmission of the disea.se. It is not impossible that ants may 

 have a role to i)lay in the transmission or cause of .sore-head." 



"Pathological Anatomy. On the skin the small, grea.sy-like 

 nodules, or hypertrophied nodules of the skin, contain epithelial 



