oronet, followed by
a slough and the formation of an ulcer which heals by suppuration.

It is an extremely painful disease, owing to the dense character of the
tissues involved; for in all dense structures the swelling which
accompanies inflammation always produces intense pressure. This pressure
not only adds to the patient's suffering but may at the same time
endanger the life of the affected parts by strangulating the blood
vessels. It is held by some writers that simple quittor is most often
met with in the hind feet, but in my experience more than two-thirds of
the cases have developed in the fore feet. While any part of the coronet
may become the seat of attack, the heels and quarters are undoubtedly
most liable.

_Causes._--Bruises and other wounds of the coronet are often the cause
of cutaneous quittor, yet there can be no question that in the great
majority of cases the disease develops without any known cause. For some
reason not yet satisfactorily explained most cases happen in the fall of
the year. One explanation of this fact has been attempted in the
statement that the disease is due to the injurious action of cold and
mud. This claim, however, seems to lose force when it is remembered that
in many parts of this country the most mud, accompanied with freezing
and thawing weather, is seen in the early springtime without a
corresponding increase of quittor. Furthermore, the serious outbreaks of
this disease in the mountainous regions of Colorado, Wyoming, and
Montana are seen in the fall and winter seasons, when the weather is the
driest. It may be claimed, and perhaps with justice, that during these
seasons, when the water is low, animals are compelled to wade through
more mud to drink from lakes and pools than is necessary at other
seasons of the year, when these lakes and pools are full. Add to these
conditions the further fact that much of this mud is impregnated with
alkaline salts which, like the mineral substances always found in the
mud of cities, are more or less irritating, and it seems fair to
conclude that under certain circumstances mud may become an important
factor in the production of quittor.[3]

While this disease attacks any and all classes of horses, it is the
large, common breeds, with thick skins, heavy coats, and coarse legs
that are most often affected. Horses well groomed and cared for in
stables seem to be less liable to the disease than those running at
large or than those which