27S Seventeenth Annual Report of the 



mouth and cheeks and also on the surface of the throat. Isolated 

 blisters may be found outside on the bare muzzle, and they are 

 common inside the nose. 



The udder and teats are very frequently involved in dairy cows, 

 the bag becoming red, hot and tender and about the second day the 

 cuticle is raised, especially on the hairless teats, in the form of 

 blisters, rounded like those on the mouth but perceptibly smaller. 

 They are usually burst by the hands of the milker, or break of 

 themselves on the second day, leaving circular reddish, granulat- 

 ing, bleeding, or scabby sores which are liable to be continuously 

 injured anew and kept up by the milking. They sometimes form 

 in the milk ducts and lead to congestion and even active inflam- 

 mation of the gland, and to dangerous secondary infections with 

 other microbes. The external sores are also liable to similar com- 

 plex and distinctive infections, and intractable inflammations, 

 with, in bad cases, complete suppression of the milk, induration 

 or suppuration of the gland and its permanent destruction. In 

 such cases the cow has a tendencv (o become an inveterate kicker. 



Upon the feet the inflammation affects particularly the arch of 

 the interdigital space, and the blisters are usually smaller than 

 even those on the teats, but they burst early and rarely come under 

 the eye of the observer. What is habitually seen is a swollen and 

 more or less tense condition of the pastern or thickening of the 

 affected limb just above the hoof, attaining its greatest tumefaction 

 opposite the ends of the cleft in front and behind, and when the 

 foot is lifted and the hoofs drawn apart, the skin forming the arch 

 is found to be raw and ulcerous from back to front, so that even the 

 edges of the horn may be underrun and loosened from the quick. 

 Here, more even than on the mouth or on the teats, a complex in- 

 fection is likely to occur and the ulceration, commencing in the 

 hairless skin of the interdigital arch, extends beneath the horn and 

 leads to the shedding of one or both hoofs. Or other complications 

 ensue, a productive inflammation developing a tumid, indurated 

 swelling, which pushes the hoofs widely apart, distorting the foot 

 and destroying its utility; or again, the ulcerous inflammation 

 extends inward so as to implicate the bones and joints, and ends 

 in extensive bony deposits and permanent irremediable lameness. 



