t calves 8
and 10 months old are frequently affected, and several cases in adult
cattle have been reported to this office.

In its very acute form many of the cases run their course in from five to
eight days. In these the local lesions are not strongly marked, and death
seems due to acute intoxication. In other enzootics the majority of the
affected animals live from three to five weeks. These are cases that
occasionally present the pulmonary and intestinal symptoms, and sometimes
develop also caseo-necrotic lesions in the liver.

Ordinarily cases show no tendency to spontaneous cure. Left to themselves
they die. On the contrary, if taken in hand early, the disease is readily
amenable to treatment. In the latter event the prospects of recovery are
excellent.

_Differential diagnosis._--Necrotic stomatitis may be differentiated from
foot-and-mouth disease by the fact that in the latter there is a rapid
infection of the entire herd, including the adult cattle, as well as the
infection of hogs and sheep. The characteristic lesion of foot-and-mouth
disease is the appearance of vesicles containing a serous fluid upon the
mucous membrane of the mouth and upon the udder, teats, and feet of the
affected animals. In necrotic stomatitis vesicles are never formed,
necrosis occurring from the beginning and followed by the formation of
yellowish, cheesy patches, principally found in the mouth. Mycotic
stomatitis occurs in only a few animals of the herd, chiefly the adult
cattle, and the lesions produced consist of an inflammation of the mouth
and lips and of the skin between the toes, followed in a few days by small
irregular ulcers in the mouth. This disease appears sporadically, usually
in the early fall after a dry summer, does not run a regular course, and
can not be inoculated.

_Prevention._--Prophylaxis should be carried out along three lines:

(1) Separation of the sick from the healthy animals.

(2) Close scrutiny and thorough disinfection once or twice daily for five
days of the mouths and nasal passages of those animals that have been
exposed.

(3) Complete disinfection of all stalls and sheds.

The disease appears to break out in winter and hold over to spring. It is
conceivable that exposure to cold might so disturb the normal circulation
of the oral tissues as to make the mucous membrane an excellent location
for the causative factor of the disease. There is another possibility,
however, which bears on the th