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WOUNDS AND BRUISES OF THE UDDER. 
particularly during lactation. The white blood-corpuscles are stated to pass 
hence even into the alveoli of the gland. This intimate relationship between 
the alveoli and the blood and lymph vessels is of the greatest importance in 
studying the development of disease of the udder. 
The skin covering the udder shows no special peculiarity; it possesses few 
or no hairs, but, on the other hand, has in places well-developed sebaceous 
glands and large papillary bodies. 
In cattle, the skin of the teats is free of glands, and has no hair. In the 
teat of the mare, especially near the opening of the milk canal, many glands 
are found. In sheep and goats, the skin of the teat is covered with a soft 
hair, and is rich in glands, particularly at its lower end. In swine, the teat is 
devoid of hair and glands; but in dogs, single hairs and sebaceous glands exist. 
(1.) WOUNDS AND BRUISES OF THE UDDER. 
LACTIC CALCULI. 
Wounds, &c., of the udder and teats are most frequent in cows, and 
are caused by treads; animals with large pendulous udders may even 
tread on their own teats when rising. Similar injuries are also caused 
by bites (from dogs) or by sharp objects like thorns, when the animal 
leaps through or over hedges. Sometimes the skin is divided, sometimes 
only bruised. 
Surface wounds—that is, such as neither penetrate the glandular sub¬ 
stance nor the milk ducts—are of no particular importance, and may be 
treated on general principles. Considerable bleeding sometimes occurs 
at the base of the teat; and should the wound open into the gland, there 
is some danger of the formation of milk fistulae. Though healing then 
appears to proceed satisfactorily, cicatrisation fails to occur, on account 
of the milk continuously flowing away. The wound nearly closes, but 
leaves a little funnel-shaped opening, termed a milk fistula. This is, 
however, only to be feared during lactation. Injuries of the teat may 
produce cicatricial contraction, and consequent difficulty in milking. 
Bruises of the udder cause bleeding, either into the gland ducts, the 
milk then being mixed with blood, or into the tissue of the gland, the 
skin, and subcutaneous tissue. The blood may be absorbed, as in other 
soft parts, or lead to formation of pus or to putrefactive changes. 
Treatment. In all deep wounds of the udder the first object should 
be to obtain healing by first intention, which will most certainly prevent 
the formation of milk sinus. Provided the injury be still fresh, and 
seem to warrant such an expectation, the edges of the wound are carefully 
disinfected and sutured. It must not be forgotten, however, that during 
lactation milk fistulae often resist the most careful treatment, though they 
readily heal when the animal becomes “ dry.” The gaping of wounds on 
the teats and escape of milk can sometimes be prevented by applying a 
well-fitting indiarubber ring, which, however, must not be too tight; 
