500 TUMOURS OF THE BREAST. 



if the horns are placed low. or the forehead is markedly convex. 

 Such inflammatory processes readily extend to the periosteum, lead 

 to necrosis of the frontal bone, and may extend to the horn core, 

 producing loosening and loss of the horns. Swelling, increased 

 warmth, and pain occur to a varying extent and degree. The 

 prognosis, however, is usually favourable, if the animals can be laid 

 off work for some time. As to treatment, the general principles 

 of surgery must be pursued. Necrotic bone and loosened horns are 

 to be removed, and the spread of inflammation checked by antisepsis. 



VII.— TUMOURS OF THE BREAST. 



In draught horses, tumours occur in and under the skin, chiefly 

 from friction of the collar. They are either single or multiple, and 

 may attain considerable size. Those in grey horses are generally 

 melanotic ; in horses of other colours they may result from infection 

 with botryomyces, staphylococci, and other pyogenic cocci, some- 

 times introduced by dirty collars. Wilhelm found enlargements 

 in the skin of the breast, each containing a small pus centre. They 

 had been treated with iodine and preparations of mercury without 

 effect. Pflug has lately described certain diseased processes of the 

 skin of the shoulder as tylomata. The cut surface in recent cases 

 often appears cedematous, and on casual examination may easily 

 be mistaken for a myxomatous growth ; the older swellings are 

 firm and hard (tylomata fibrosa, Pflug). Nor is it astonishing that 

 new growths often rise from the cutis or subcutis, considering the 

 chances of infection here on account of the epidermis below the collar 

 being macerated and not infrequently injured. Many horses in the 

 same stable have been seen to suffer from this disease, the tumours 

 appearing under the collar and producing inflammatory swellings 

 from bruising. In horses, local centres of suppurative inflammation 

 occur in the shoulders, forming little nodules. They originate in 

 the sebaceous and hair glands, and are commonest during warm 

 weather. If they remain unnoticed and the animals be kept at 

 work, inflammation spreads and abscesses form in the site of the 

 glands. 



Prognosis of such enlargements depends on their extent and 

 position, usually determined by careful palpation. Small tumours 

 are extirpated with the scissors, large with the knife ; when taken 

 in hand early, recovery is usually complete, although recurrence is 

 not infrequent. If the neglected swelling attains a considerable 

 wze, possesses a broad base, or extends to the pre-scapular lymphatic 



