Stickler said that he had produced scarlatina in children by
inoculation with imported virus of foot-and-mouth disease, but his
contention is negatived by the facts that with foot-and-mouth disease
constantly present in Europe scarlatina does not accompany it, and that in
America, with scarlatina constantly prevailing at some point,
foot-and-mouth disease is unknown locally except at long intervals and as
the result of the importation of infected animals or their products. Man is
susceptible to foot-and-mouth disease, but it never appears during the
frequent epidemics of scarlatina.

Among other contagious forms of mammitis I may name one which I have
encountered in large dairies, starting as a sore and slight swelling at the
opening of the teat and extending up along the milk duct to the gland
structure in the bag, all of which become indurated, nodular, and painful.
The milk is entirely suppressed in that quarter of the bag, and from that
it may extend to the others as it does from cow to cow through the milker's
hands.

Another form almost universally prevalent in this district of central New
York in 1889 broke out on the teats and udders as blisters strongly
resembling cowpox, but which were not propagated when inoculated on calves.
It was only exceptionally that this extended through the teat to the gland
tissue, yet in some instances the bag was lost from this cause. Scarlatina
in man was very prevalent at the time (many schools were closed in
consequence), but no definite connection seemed to exist between this and
the cow disease, and on different dairy farms there were families of young
children that had never had scarlet fever and who did not at that time
contract it.

The most common cause of contagious mammitis in cattle is a spherical
bacterium in chain form (_Streptococcus_) (Moore, Ward). Yet it is clear
that contagious mammitis is not a single affection, but a group of diseases
which have this in common, that they attack the udder.

_Prevention._--Prevention is to be especially sought in all such cases. In
purchasing new cows see that they come from a herd where the teats and
udder are sound. If a new cow with unknown antecedents comes from a public
market, let her be milked for a week by a person who does not milk any
other cows. Keep her in a separate stall from others, so that there may be
no infection from litter or flooring. Wash the udder with soap and water,
and wet with a solution of two teas