diseases of the digestive organs.

DISEASES OF THE SKIN. 329Causes.—Erythema simplex, consisting of an inflammatory irritation,is witnessed in very young calves, in which the navel leaks. Thedischarge being urine, it causes au irritation of the surroundingskin. Erythema intertrigo is that condition known as chafing, and isoccasionally seen on the udder of cows from chafing by the legs; chafingbetween the legs is not uncommon among fat steers. Erythemachronicum, or mammillarum, is found in the form of chapped teats ofcows and chapped lips in suckling calves. It frequentlyoccurs in cowswhen they are turned out in winter directly after milking, and in othersfrom chafing by the calf in sucking. Some cows are peculiarly subjectto sore teats. The fissures when neglected in the early stage of formationbecome deep, very painful, often bleeding at the slightest touch,and cause the animal to become a kicker when milked in that condition.Occasionally the lower portions of the legs become irritated and chappedwhen cattle are fed in a muddy or wet yard in winter, or if they arecompelled to wade through water in frosty weather.Treatment.—In ordinary cases of erythema, the removal of the causeand the application of benzoated oxide of zinc ointment, carbolizedcosmoline, or a mixture of creolin, 1 ounce to a pint of water, applieda few times, will restore the skin to a healthy condition.When there are fissuresthe zinc ointment is the best. If at the teats,a milk syphon (Plate xxiv, Fig. 4) should be used instead of milkingby hand, and the calf, if there is one suckled, should be taken away.When the calf s mouth is affected it should be fed by hand. When thelegs are irritated or chapped, dry stabling for a few days and the applicationof tar ointment will soon heal them.URTICARIA—NETTLE RASH—SURFEIT.This is a mild inflammatory affection of the skin, characterized bysudden development of patches of various sizes, from that of a nickelto as large as the hand. The patches of raised skin are marked by anabrupt border, and are irregular in form. All the swelling may disappearin a few hours, or it may go away in one place and reappear onanother part of the body. It is always accompanied by a great desireto rub the affected part. In its simplest type, as just described, itis never followed by any serous exudation, or eruptions, unless thesurface of the skin becomes abraded from scratching or rubbing.Another type of urticaria, known as lichen urticatus, by some writersdesignated prurigo vernalis or spring itch, is manifested by the eruptionof small vesicles upon the swollen parts of the skin. These disappearmore slowly and are followed by loss of the hair of the affectedareas. This form of the disease is more apt than the former to becomescattered over the whole body. Its duration greatly depends upon thepresence or the removal of the exciting cause. Occasionally therelapses are so frequent that it finallybecomes a chronic disorder.Causes.—Derangements of the digestive organs are the most common