FIFTEENTH ANNUAL REPORT 107 



Diphtheria or Roup m Wild Birds. — Diphtheria or roup in 

 wild birds is an infectious disease, the lesions of which first 

 appear on the mucous membrane of the eyes, nasal passages, the 

 mouth, the pharynx and larynx, and may extend to the trachea, 

 bronchi and air-sacs. 



The specific cause of the disease known as diphtheria or 

 roup has not been positively determined. 



It is recognized by a grayish-yellow, fibrinous exudate which 

 forms upon the mucous surfaces of one or more of the parts 

 mentioned. The exudate may be so abundant as to obstruct the 

 air passages. The disease is usually very acute, progresses with 

 great rapidity and destroys most of the birds attacked. 



Among wild birds in captivity, the disease is common in 

 hawks, vultures, owls, eagles, pheasants, quail, pigeons, storks, 

 flamingoes, ducks, and various other water birds. Avian diph- 

 theria is apparently quite distinct from human diphtheria. 



Symptoms. — At the outset of the disease there is a watery 

 discharge from the nostrils and ej'es, with general weakness and 

 prostration greater than would be expected from simple catarrh. 

 The birds sit with the back arched, the head and neck drawn 

 toward the body, the plumage roughened. Respiration is more 

 or less obstructed, rapid and audible; the vision is impaired and 

 swallowing difficult. There is frequent shaking of the head, 

 sneezing and expectoration of mucous secretions. Within a day 

 or two the appetite disappears, and there is a diarrhea with 

 greenish or yellowish evacuations. From the open beak there 

 escapes a thick, stringy, grayish mucous; the eyes project un- 

 naturally and are covered with the thick secretion which has ac- 

 cumulated between the lids; the nostrils are obstructed by the 

 thickened and dried secretions; the mucous membrane of the 

 mouth and pharynx is congested and shows numerous dark red 

 elevations covered with fibrinous exudate, and later these patches, 

 consisting of thick masses of exudates, become milky white or 

 yellowish brown in color, and if removed leave behind a more or 

 less granular and healed surface. 



Prevention. — In order to prevent this disease many condi- 

 tions must be strictly enforced. In addition to the general sani- 

 tary methods, the following rules should be observed : 



1. Birds which have an exudate on any of the mucous mem- 

 branes of the head should not be placed among healthy stock. 



