DISEASES OF THE RESPIRATORY PASSAGES 177 



(cMvity) in front and ])olow the eye. This is dne to an accn- 

 nmhition of the inflaininatory products in this sinus. Pig, 66 

 illustrates this common swelling. 



2. The iliphtheric type. — This type affects the mouth and 

 often accompanies the nasal form. Fig. 67 illustrates diph- 

 theric ulcerations, which are yellowish or yellowish-white in 

 color. From these necrosing patches the disease receives its 

 name, avian diphtheria. 



The ocular type. — In this form there is first noted an 



o 

 O. 



Fig. 67. Diphtheric Roup in a Chicken. 

 A, the yellowish-white diphtheric patches on upper surface of tongue 

 and lower jaw (natural size); B, diphtheric patches on hard palate and 

 upper jaw. 



inflammation of the mucous membrane covering the anterior 

 portion of the eyeball (conjunctivitis). As the disease pro- 

 gresses, the catarrhal product accumulates as a watery, clot- 

 like mass, whitish in color. The eyelids stick together and 

 hold the material as it accumulates, till the part bulges out- 

 ward. 



There is noted sneezing, shaking the head, and expulsion of 

 mucus. There is a loss of appetite, the bird appears weak, 

 walks unsteadily, and becomes emaciated rapidly. At times 

 breathing is difficult, and there is often a diarrhea. 



