36 GUAM AGRICULTURAL EXPERIMENT STATION. 



disease becomes especially serious, rendering the bird blind, and 

 resulting in starvation, since the chicken is unable to locate its food. 



M()S(iuitoes, chicken lice, and mites are held to be factors in trans- 

 mitting the disease, and cockfighting in Guam doubtless plays an im- 

 portant part in its spread. Any abrasion of the skin affords an ex- 

 cellent avenue of entrance for the germ of this disease. 



CHOLERA. 



Two outbreaks of chicken cholera were investigated during the 

 past year. From reports here it seems safe to say that cholera has 

 done more to discourage the poultry industry than any other factor. 

 The symptoms and post-mortem findings have been similar to those 

 in the United States, and consequently it does not seem necessary to 

 go further into detail. 



DIPHTHERITIC ROUP. 



Diphtheritic roup is present in all parts of the island (PL VII, 

 fig. 2). In most cases, chicks between the ages of 2 and 6 months are 

 affected, although it is not uncommon to see the disease manifesting 

 itself among mature fowls. 



Investigational work here has shown as many as 50 per cent of a 

 brood of young chicks to have been affected with diphtheritic roup, 

 and the mortality among untreated chicks has been as high as 90 

 per cent. 



On this island, the presence of rain and dampness seems to play no 

 important part in producing this disease. This is shown by the fact 

 that the disease appeared this past year well after the dry season had 

 set in and has remained stubbornly and persistently through the past 

 three exceedingly dry months. The disease first appeared at this 

 station when chicks about 2 months old were placed in a house and 

 run which had previously been occupied by mature fowls. The 

 chicks were allowed to seek shade under the house wdiere the soil was 

 dry and dusty. 



While the mucous membranes of the eyes, nostrils, and mouth are 

 most often affected, the disease has been found in the crop, proven- 

 triculus, and gizzard, setting up in these places a catarrhal condi- 

 tion. The first symptom noted is an acute conjunctivitis of the mu- 

 cous membranes of the eye (usually appearing in but one eye at 

 first, but in most cases affecting the other eye later). The affected 

 eye is watery, with a slight watery discharge from the nostrils. A 

 thick catarrhal product, wdiite in color, soon begins to accumulate 

 in the eye, while the nostrils become plugged with a thick, caseous 

 material. Ulcerated areas, w^hite or yellowish-white in color, ap- 

 pear in the mouth. The bird becomes weak, dull, and emaciated, with 



