udder the erosions will often be found
within the passages of the teats, resulting in a "caked" udder, and the
same toxic poisoning which is the cause of death in the apoplectiform types
just mentioned may arise from this source. In any event the milk from such
cases is dangerous for use, causing fatal diarrhea in sucking calves or
young pigs and serious illness in human consumers. The milk obtained from
cows suffering with foot-and-mouth disease is not readily converted into
either butter or cheese, but remains thick, slimy, and inert in spite of
churning and attempts at curdling. Pregnant animals may abort. In pigs,
sheep, and goats the lesions in the foot are most common, but both forms
may be observed or only the mouth lesions.

When the disease has become fully established it will be found that the
duration of the attack will vary greatly with different animals. From 10 to
20 days are usually required for the recovery of the normal appetite and
spirits in mild outbreaks, while the return to a full flow of milk, in the
case of milk cows, seldom occurs before the arrival of the following
season.

In the malignant type of the disease it requires from three months to a
year for an animal to recover. The mortality, as already stated, is usually
low. The disease is more fatal in young animals that have been fed on
infected milk, and produces death in from 60 to 80 per cent of these cases
as a result of gastroenteritis. In the 1914 outbreak numerous new centers
of infection started among hogs and calves which were fed on unpasteurized,
infected milk from creameries.

_Diagnosis._--The recognition of this affection should not, as a rule, be
difficult, especially when the disease is known to be in the vicinity; in
fact, the group of symptoms form a clinical picture too decided to be
doubted. The combination of high fever, vesicular inflammation of the
mouth, and hot, painful, swollen condition of the feet, followed 24 to 48
hours later by the appearance of numerous blisters varying in size from
that of a pea to that of a walnut on the udder and feet and in the mouth
should prevent any serious or long-continued error in the diagnosis;
however, in the inoculation of calves we have a certain and final test. In
24 to 96 hours after inoculation the calves present the characteristic
blisters. Such inoculation should be practiced, however, only by officials
properly authorized to deal with contagious diseases.

_Differential di