41^ 



336 THE PRACTICE OF VETERINARY MEDICINE. 



marked sj^mptom, especially when one foot only is affected, 

 is atroph}'' of the inside quarter of the hoof, and contraction 

 of the heels. The quarter has a peculiar straight appear- 

 ance. This is after awhile succeeded by a general decrease 

 in the size of the foot, in consequence of the soft tissues 

 contained within the hoof having become atrophied, the 

 atrophy being more or less due to functional inactivity, 

 the foot not being used as much as it should be, the 

 ,nimal resting it whenever opportunity otfers. The horny 

 frog usually presents a small and shrivelled appearance, 

 in some cases dwindling in size until scarcely any frog 

 remains. The fatty frog is also affected in such cases 

 and there is frequently observable a well-marked concavity 

 of the sole; the animal shows a disposition to go upon the 

 toe, and has a strong tendency to stumble. In some cases, 

 while driving or riding an animal in which no positive 

 symptoms have as yet been observed, he suddenly stumbles, 

 and almost or quite falls, even when on a perfectly level 

 piece of road where nothing can be discoverd to account 

 for his stumbling. In a day or two afterwards a slightly 

 abnormal degree of heat may be discovered to exist in the 

 foot, but he is bathed, etc., and it disappears, only to re- 

 appear in a short time, when it may be slightly more 

 troublesome to get rid off. Thus it goes on for two or 

 three months, or longer, before any well-marked symptoms 

 of the disease appear. Such symptoms are premonitory of 

 navicular disease. The symptoms of navicular disease are also 

 said to be negative and positive. The negative evidence of 

 navicular disease is absence of disease in any other part 

 of the limb, and the practitioner may be often struck with 

 the fine clean appearance of the affected limb, there being 

 no wind-galls or anything of that sort to mar its symmetry, 

 the general appearance of the limb being much finer than 

 that of its fellow. Soon general atrophy of the limb takes 



