mains
still unknown, is transmitted mainly during copulation. The bull may have
the disease and convey it to all the cows with which he comes in contact,
or he may become infected by one cow, and, although not showing the
disease, he may, during copulation, transmit it for several days after to
all other cows. Simple contact between one cow and another may convey the
disease, or the sponges used in cleaning the diseased may carry the virus
to the healthy. It has also been conveyed to healthy cows by these animals
lying with their hind quarters against infected wooden troughs.

_Symptoms._--The period between the infection and the appearance of
symptoms is somewhat variable. It is usually given as three to six days. It
may be briefer or much longer. In cows the mucous membrane of the vagina
and the vulva become swollen, inflamed, very tender, and covered with
dark-red spots. The secretion is very abundant and consists at first
largely of serum and mucus resembling the white of an egg. Small vesicles
then appear, which rapidly burst and are converted into excoriations or
deeper ulcerations. The secretion becomes more purulent and is apt to dry
in crusts about the root of the tail. The eruption is accompanied with much
itching and difficulty in urinating. The walk may be stiff and awkward. In
bulls the eruption is situated on the prepuce and the end of the penis, and
consists of pimples, vesicles, and ulcers, as in cows. It is accompanied
with a little purulent discharge from the prepuce, itching, and difficulty
in urinating. In severe cases the inflammation and swelling may extend
backward to the scrotum and forward upon the abdomen.

The disease lasts from one to four weeks and always terminates in recovery.
The acute stage lasts only four or five days, while the complete healing of
the inflammation is slow. The eruption is usually accompanied with very
little general disturbance. If the pain and irritation are severe, there
may be some light loss of appetite and diminished milk secretion in cows.
The disease rarely causes abortion. Chronic catarrh of the vagina and
permanent sterility frequently follow as sequelae.

_Treatment_ need not be resorted to excepting in severe cases. The
secretion and exudation should be washed off and a mild antiseptic applied,
such as a 1 per cent solution of carbolic acid (1 ounce to 3 quarts of
water) or 2 per cent solution of cresol compound in water. Care must be
taken not to carry the