Etiology. Pathogenesis. Symptoms. 19X 



it was identical with a disease described by Hess in 1899, under the name 

 stomatitis follicularis, and by Degive (1884) as stomatitis papiUaris. 

 The sporadic aphthous disease of Deppe (1899) and the infectious 

 stomatitis seen by Haag (1907) in Bavaria likewise appear to be iden- 

 tical with this disease. According to Tiarks (1904), it is common in 

 the Prussian provinces of Posonia and East Prussia. Finally, some of 

 the diseases called pseudo foot-and-mouth disease of cattle {q. v.), prob- 

 ably are also identical with this affection. 



Etiology. The cause of the disease is an ultramicroscopic 

 microorganism which is found in the pathologic lesions and in 

 the blood of the sick animals. 



Pathogenicity. When particles of the pathologically 

 changed mucosa are inoculated into the buccal mucosa of 

 healthy cattle, they produce the disease in its typical form ; it 

 can also be produced by suljcutaneous and intravenous injec- 

 tions of the blood of sick animals. Filtered blood serum also 

 caused the disease in the experimental animal in one case, but 

 it was not effective in subsequent transfer experiments, although 

 the defibrinated l)lood of the same animal remained virulent. 

 If the pathologic products are transferred to the nasal, ocular 

 or vaginal mucosa, the disease is not produced. Spontaneous 

 transmission to healthy calves has also been observed. Younger 

 animals are more susceptible than older ones. 



How natural infection is produced has not yet been shown. 

 The experiments of Ostertag & Bugge make it possible to be- 

 lieve in an inoculation with the food through injuries in the 

 buccal mucosa. 



Pathogenesis. The blood vessels are dilated in circum- 

 scribed places of the buccal mucosa ; this is followed by migra- 

 tion of leucocytes into the hanph spaces in the neighborhood 

 of the blood vessels of the superficial layers of the mucosa, and 

 between the epithelial cells of the stratum germinativum ; in 

 consequence of this, the epithelial covering and the papillse of 

 the mucosa become thickened. In the meantime the epithelial 

 cells become vacuolated; this vacuolation increases toward the 

 surface and a desquamation of epithelia occurs, so that the 

 papillae remain covered only by the deepest epithelial layers. 

 In the further course of the process, the epithelia covering the 

 elongated papillae proliferate and form a new covering. If the 

 upper portion of the papillae has been destroyed, the latter suf- 

 fer a diminution in size. 



Symptoms. The incubation stage after artificial infection 

 lasts an average of two weeks, although transitory, but not 

 characteristic, s^Tiiptoms may sometimes appear after seven to 

 eight days. Flat nodules of from millet seed to lentil size ap- 

 pear on the internal surfaces and on the margins of the lips, 



