DISEASES OP THE OX AND SHEEP. 349 



even last three months. Cows which have recently calved seem 

 to be especially liable to the disease. Perhaps they have been in 

 bad condition before calving, or they may have slipped their 

 calves, or possibly portions of the membranes have been retained, 

 and the animals thus debilitated have been a ready prey to the 

 germs of the malady. 



The bowels are rather loose, and the urine is scanty and high- 

 coloured. About six days after the beginning of the illness, one 

 or more teats become enlarged, swollen so as to be nearly double 

 their natural size, puflfy, and not at all hard. Little bladder-like 

 spots next appear upon the red and greatly enlarged teats and 

 on the udder. There may be about three of these on one teat. 

 They are about the size of a pea, and contain a clear fluid. They 

 break and leave raw sores or ulcers, which are red or pale, and 

 have raised edges. In about two days' time the little bladders 

 have become ulcers of about half an inch in diameter. Shortly 

 after being broken, a reddish-brown scab begins to form in the 

 centre of the sore and extends towards the margin. These scabs 

 may remain attached, perhaps twenty-five days, or even as long 

 as six weeks. A watery fluid exudes from under the scab, and 

 about six days after the ulcers have become covered with the 

 scabs, they gradually heal up, leaving a whitish, flat, indistinct 

 scar. 



About six weeks after the cows had been first attacked, the 

 scabs varied in size from a shilling to that of a florin ; the skin 

 beneath was of a pearly-blue colour and slightly hardened, but 

 not depressed. After the vesicles had broken and the scabs had 

 formed as described above, the swelling of the teats gradually 

 subsided. The margins of the ulcers were not raised, and there 

 was no perceptible redness of the skin around them. In some 

 animals an ulcer here and there was seen on the lower part of 

 the udder. 



It may be observed that in the case of cow-pox a hard spot 

 first appears, and then becomes bladder-like, while pus develops 

 in it. In the centre of the little bladder-like elevation (vesicle) 

 there is formed a depression with raised pearly-looking edges, 

 with hardening round the margin, and with a distinct areola. 

 In the case, however, of this disease which we are considering, 

 the vesicle seems to appear at once without being preceded by a 

 hard spot, without the development of pus, without the central 



