Summer disease. Depilation. Scaly. Itchy at first. Lesions of bones,
red zones representing successive attacks. Alterative tonics
indicated.
Megnin records the case of an ox which on three successive springs had a
miliary vesicular eruption on the loins and upper walls of the abdomen,
which persisted until the advent of cold weather in the fall. The
vesicles were followed by an exudate which concreted in solid crusts,
enveloping the roots of the hairs which were lifted from the follicles
and failed to be renewed, so that the animal entered on the winter with
an appearance of alopecia. The denuded surface was red, shining and
covered with a dense covering of lamelliform epidermic scales. In the
early stage of the eruption there was moderate pruritus, but when the
scaly stage was reached it was neither tender nor itchy to any marked
degree. Tar ointments had no effect in stimulating the growth of the
hair, and the skin remained bald until the next attack. The second and
third years the eruption extended farther, invading not only the trunk,
but the legs, and passing through the same successive stages.
The animal was butchered and the shafts of the bones were found to be
abnormally red, and showed three concentric rings of deeper brown,
manifestly representing the three acute attacks and resembling the
concentric rings formed in growing bones when the young animals are fed
on madder.
The manifest disorder of nutrition in this chronic skin disease, is an
argument for the _treatment_ by alterative tonics, such as arsenic, as
well as for the employment of tonics and corroborants in general. In
such cases the presumption is that local treatment would be useless or
nearly so until the general disorder could be repaired.