FOOT-AND-MOUTH DISEASE. 
487 
organ they are surrounded by a pale-red circle, and when conflu¬ 
ent they are very irregular and variable in number. In the case 
of a cow the alteration of the milk is very striking. It coagulates 
on being boiled, or when its temperature is only slightly raised. 
It also becomes yellow in color and acid in reaction. 
When the limbs are affected the heat and redness of the coro¬ 
net are most noticeable toward the heel and interdigital space of 
one or more feet. The coronet swells; the animal is lame, and 
prefers to maintain a recumbent position. In one or two days the 
vesicles are developed at the points indicated, most frequently 
earliest in the intedigital space ; at first they are small, but they 
increase in size until they are as large as a bean or small nut, and 
extend round the claws, often becoming confluent, the contents 
appearing as a yellow limpid fluid. The skin of the part assumes 
a bleached aspect, and is soon covered with a kind of cheesy mat¬ 
ter, resulting from the inspissation of this fluid, which emits an 
ammoniacal odor. In some cases the skin around the base of the 
horns becomes inflamed at the same time as that of the mouth or 
feet, and the horns are loosened. Occasionally, also, a vesicular 
eruption manifests itself at the orifice of the vagina, at the peri¬ 
neum and anus, or in the nostrils ; and it sometimes happens that 
the eyes are affected, the conjunctival membrane becoming in¬ 
flamed and suppurating, and phlyctense forming on the cornea- 
There may also be nasal catarrh and symptoms of gastric derange¬ 
ment. 
Third Period. This is the aphthous stage of the disease, and 
begins when the vesicles have ruptured, and the epidermis being 
removed, erosions appear. This does not occur everywhere at the 
same time, but varies according to the region. In the mouth it 
soon occurs, owing to the movement of the tongue, and also in 
the feet by that of the claws. On the udder it is later, seldom 
occurring before*thirty-six or forty-eight hours; or if the disease 
is benignant the vesicles on this organ may not rupture at all, 
their contents becoming absorbed, and the pellicle of epidermis 
covering them scaling off when cicatrization has taken place be¬ 
neath. When the vesicles do break, there remains a little, bright- 
red sore, which is smooth or granulating, and is soon covered with 
