Any form of senile decay would be reckoned amongst atrophies, but the condition is rarely observed in the horse excepting as the result of continuous pressure on a particular part. The hair appears to suffer from this change more than other of the cutaneous structures.

Fig. 269. - Section of Wart.

A, Horny Epidermis. B, Deep Layer of Germinal Cells, c, Fibrous Stroma. D, Blood-vessel.

New Formations

Of the diseases included in this group, i.e. cancer, lupus, and rodent ulcer, the first is the only one which is recognized in the horse. The disease in that animal is of rare occurrence, and usually affects the internal organs. It can scarcely be referred to, therefore, as a skin disease.