378 The Diseases of Animals 
A vaccine against contagious abortion has been pre- 
pared, and recently placed on the market, that promises 
to be of great value in dealing with this serious disease. 
Cows should be kept in fair flesh and in a good, vigorous 
condition. 
FOOT-AND-MOUTH DISEASE 
Foot-and-mouth disease is a highly infectious dis- 
order, attacking cattle principally, but easily trans- 
mitted to sheep, goats, pigs, and other domestic animals. 
Man frequently contracts the disease from infected 
animals. It is generally considered to be a germ dis- 
disease, although the specific organism has not been 
discovered. This disease has been known for many 
vears in Europe, and immense losses have followed its 
ravages, some parts of Europe rarely being free from 
it, and in other parts outbreaks occurring at irregular 
intervals. One attack of the disease does not confer 
Immunity, as an animal may have it several times. 
Foot-and-mouth disease varies in virulence. In 
some outbreaks many animals die, but in most eases the 
mortality is not high, the greatest loss resulting from a 
falling off in flesh and general deterioration resulting 
from the disease, and the necessary restriction of the 
live-stock trade which follows. The disease is trans- 
mitted by direet contact, and through the medium of 
infected food, litter, watering places, stables, cars and 
attendants. It is possible that the contagion may be 
earried short distances in the air. The milk of an 
affected animal is highly dangerous. The period of 
incubation, or the time that elapses between exposure 
