398 DISEASES OF CATTLE. 



1 he observations made by some veterinarians would lead us to sup- 

 pose that the virus is quite readily destroyed. It is claimed that 

 stables thoroughly cleaned become safe after drying for a short time. 

 Hence litter of all kinds, such as manure or soiled hay and straw, 

 may remain infective for a longer time because they do not dry out. 

 Other authorities maintain that the virus is quite tenacious and may 

 live in stables even so long as a year. They also state that animals 

 which have passed through the disease may be a source of infection 

 for several months after recovery. 



/Symptoms. — In three to six days after the exposure of the ani- 

 mal to the infection the disease makes its appearance. It is first 

 indicated by the animal suffering from a chill, quickly followed 

 by an invasion of fever, which may cause the temperature to rise as 

 high as 106° F. Following this, in one or two days it will be noticed 

 that small vesicles about the size of hemp seeds or peas are making 

 their appearance upon the mucous membranes of the mouth at the 

 border and upper surface of the tongue near the tip, the inside of the 

 cheeks, on the gmns and the inner surface of the lips, or on the mar- 

 gin of the dental pad. These little blebs contain a yellowish watery 

 fluid and gradually become more extensive as the disease advances. 

 Soon after the eruptions have appeared in the mouth of the animal it 

 will be noticed that there is considerable swelling, redness, and ten- 

 derness manifest about the feet, at the coronet and between the digits 

 of each foot. Eruptions similar to those within the mouth make their 

 appearance upon these swollen regions of the foot a day or two later, 

 and at this stage it is usual to find that like lesions have made their 

 appearance upon the perineum of the victim. In the case of milch 

 cows the udder and more particularly the teats show the same vesicu- 

 lar eruption, but the latter as the result of milking soon become cov- 

 ered with reddened spots deprived of the superficial layer of skin and 

 may develop deep, obstinate fissures. 



As soon as the disease has become well established the patient 

 evinces pain when attempting to eat ; in fact, the appetite is often so 

 seriously affected that all food is refused and the animal uneasily 

 opens and shuts its mouth with a characteristic smacking sound, 

 while strings of cohesive, ropy saliva hang suspended from the lips. 

 With the advance of the disease the vesicles have widened and ex- 

 tended until they may reach a diameter ranging from that of a dime 

 to that of a silver dollar. These rupture soon after their appearance, 

 sometimes on the first day, more rarely on the second or third day. 

 After they have ruptured the grayish white membrane forming the 

 blister may remain attached for a day or more or disappear speedily 

 and leave deeply reddened sensitive spots or erosions behind, both 

 within the mouth and upon the coronet and between the claws of tlie 

 feet. The same ulceration may be noticed in cases in which the teats 



