332 Foot-and-Mouth Disease. 



1 to 3 days after the injection, in the mouth, in cows also on 

 the udder, and 1 to 2 days later also on the feet, these eruptions 

 being associated with febrile manifestations. Infection may 

 also result from rubbing the lymph upon the superficially scari- 

 fied mucous membrane of the mouth, by dropping the virus on 

 the conjunctiva, the rectum or the vaginal mucous membrane, 

 and further by intra-muscular, intra-peritoneal injections, like- 

 wise by inoculation of the milk ducts. Placing woolen threads 

 dipped in lymph, between the teeth, and sometimes also feeding 

 gelatin capsules filled with virulent lymph, may give positive 

 results, while a subcutaneous infection is uncertain. Should 

 virulent lymph be injected into the milk cistern of a fresh milk- 

 ing cow, local inflammation of the milk ducts develops, and the 

 milk proves virulent for a period of eight days (Nocard). The 

 most effective is the lymph of infected hogs, then that of cattle, 

 while the least efficient is that from sheep. The artificial infec- 

 tion of goats and sheep is in general quite difficult. Young dogs 

 and cats are very susceptible to artificial infection (the vesicles 

 develop in these animals between the digits), exceptionally 

 guinea pigs- and rabbits may also become affected (Hecker), 

 while mice and fowl, as well as older, carnivorous animals, are 

 resistant to inoculation. Young pigs die after several days from 

 paralysis of the heart after an inoculation of 1/10 to 1/50 cc. 

 of fresh lymph. The autopsy in such cases reveals a great 

 amount of serous fluid in the pericardium, which contains the 

 virus in pure culture (Loffler, Nocard). 



Natural infection often occurs directly, healthy animals 

 coming in contact with affected cases, in the stable, pasture, or 

 yards, by means of which they receive the virus upon their 

 mucous membranes. Infection with inhaled air has not yet been 

 proven, and could only occur within very short distance, in damp 

 weather, or in the stable. 



Indirect transmission has a far greater importance in the 

 spread of this disease. The saliva, which flows from the mouths 

 of affected animals, and also the contents of the udder or the 

 vesicles which develop on the feet, contaminate the food, the 

 cribs, the drinking water, the straw, the stable floor, the pas- 

 ture, the highways, the railroad cars, etc., as well as the hands 

 and the clothes of the attendants. From such contaminations, 

 or from the floor, the virus reaches the mucous membrane of 

 any body opening, or with the food or drinking wat^r it enters 

 the mouth and stomach of the healthy animal, from which points 

 it enters the blood circulation. The virus is accordingly dissem- 

 inated in the first place by affected animals during driving, rail- 

 road transportation, stabling, by common drinking places, com- 

 mon pastures, and yards. In the second place food, manure, and 

 raw animal products, especially raw hides, wool and milk may 

 be considered as carriers of the infection. Butchers, dealers, 

 peddlers, castrators, and other persons, first of all farm hands, 



