Contagious Nasal Catarrh of Birds, 9 



or spring. It is epizootic in character and often causes the 

 death of many birds. Its economic importance depends both 

 upon the great mortality and upon the fact that affected adult 

 hens are unfavorably influenced as to their egg-laying capacity. 



Etiology. Contagious nasal catarrh of fowls is due to an 

 infection. This is shown not only by the epizootic occurrence 

 but also by inoculation experiments (authors' observations), 

 and by the observation that the disease is often imported 

 through newly bought fowls (Ammenschlaeger, Feld). The 

 nature of the infectious virus has not been determined exactly, 

 but it is contained in the secretions of the mucosa of the head. 



L. Gallez and later on Gratia & Lienaux found in the mucous secre- 

 tion from the nose of sick chickens an organism similar to the diph- 

 theria bacillus of Klebs-Loeffler. Gallez believed these bacilli to be an 

 attenuated type of the diphtheria bacillus, while Gratia & Lienaux con- 

 sider it doubtful whether the organism is an attenuated diphtheria 

 bacillus or a pseudodiphtheria bacillus. Deich demonstrated spirilla- 

 like organisms and also short bacilli rounded at both ends and occurring 

 in groups. 



The disease has formerly, but also again lately, been considered as a special 

 clinical variety of fowl diphtheria (Colin, Schrevens, Gallez, Klee) due to the 

 bacillus of fowl diphtheria. 



Natural infection takes place by scattering the infected 

 nasal secretion by movements of the head and in sneezing of the 

 sick birds and by the ingestion of these secretions with con- 

 taminated food or water by healthy birds. Healthy flocks 

 usually become infected by the importation of infected birds. 

 The disease may, however, be spread just as in fowl diphtheria, 

 by free flying birds coming from a distance. 



Predisposing causes may likewise play a role. Damp and 

 cold weather in the fall and spring, the sojourn in cold and 

 drafty places, may assist in bringing about the infection. 



Susceptibility. Young birds or such debilitated from any 

 cause, especially young chickens, are affected most commonly. 

 In some epidemics birds are affected without reference to 

 age. 



Deich did not succeed in the experimental transmission of the disease to 

 chickens and ducks. 



Anatomical Changes. Aside from emaciation and anemia 

 a glassy or purulent mucus is found in the conjunctival sac, 

 in the nasal cavities and in the pharynx. The mucosa of these 

 parts is reddened. Pseudomembranous deposits or other or- 

 ganic changes are absent. 



Symptoms. The disease begins with malaise. The sick 

 animals separate themselves from others and sit quietly with 



