VESICULAR STOMATITIS OF HOUSES AND CATTLE 3 



beginning of the disease. Other names which have been applied to 

 this affection are sporadic aphthae, stomatitis vesiculosa, stoma- 

 titis aphthosa, erosive stomatitis, sore mouth, " blue tongue/' and 

 pseudo foot-and-mouth disease. 



ETIOLOGY 



The literature upon the subject of vesicular stomatitis fails to 

 incriminate definitely any specific organism as the cause of this 

 contagion. Repeated cultural studies of fresh vesicular fluid drawn 

 under aseptic precautions from experimentally infected horses and 

 from field cases have resulted in the isolation of a Variety of micro- 

 organisms including micrococci, several short rod-shaped bacilli, one 

 of which takes the bipolar stain, a large Gram-negative spore-bearing 

 rod, and a fungus. Horses and calves were subjected to inocula- 

 tions with cultures of these several organisms, both intravenously 

 and by scarification of the epithelial covering of the tongue and inner 

 surface of the lips, but in no instance was the inoculation successful. 

 An inoculation test of a small micrococcus isolated and cultivated 

 under strict anaerobic environment proved it to be inocuous to 

 horses and calves. Finally, fresh vesicular fluid passed through a 

 Berkefeld (N) filter was completely divested of all infectious quali- 

 ties as determined by inoculation tests of the filtrate in six different 

 experiments. 



Microscopic examination of fresh vesicular fluid by dark-field 

 illumination revealed the presence of micrococci and in addition 

 small bodies with refractive coverings which were very similar in 

 appearance to the spores of a fungus isolated on egg medium from a 

 sample taken from a case of vesicular stomatitis. 



A bacteriological report of the work done by Dr. George Mathers, 

 of the University of Chicago, on the etiology of this disease was read 

 at an annual meeting of the United States Live Stock Sanitary 

 Association, 1 but the evidence presented in favor of the bacillus 

 described was far from conclusive. Through the courtesy of Dr. 

 James Gregg, of the British remount station at Newport News, Va., 

 several cultures of a microorganism which he had isolated from a 

 case of vesicular stomatitis in a mule and with which suspicious 

 sypmtoms of the disease were induced in other mules, 2 were ob- 

 tained for study. With this organism, which proved to be a faculta- 

 tive anaerobe and very slow to develop on any medium, we were 

 unable to infect horses or calves by direct inoculation of large 

 amounts of the culture. Moreover, the employment of this organ- 

 ism, as well as several other different organisms, as an antigen in the 

 complement-fixation test failed to give positive results with sera from 

 either immune horses or immune cattle. 



SYMPTOMS AND LESIONS 



The first phenomenon of vesicular stomatitis consists in the 

 formation of reddened patches on the buccal mucosa, especially of 

 the tongue. These are quickly succeeded by vesicles or blisters of 

 grayish-red color only slightly elevated and of various sizes from a 



1 Report of Twentieth Annual Meeting of the United States Live Stock Sanitary Asso- 

 ciation, December, 1916, p. 33. 



2 American Journal of Veterinary Medicine, vol. 12, No. 4, April, 1917, p. 221. 



