410 



of the navicular "bone the animal points the affected foot while at rest, 

 a time before any lameness is seen. While at work he ai^pareutly 

 travels as well as ever, but when placed in the stable one foot is set 

 out in front of tlie other, resting on the toe, with fetlock and knee 

 flexed. After a time, if the case is closelj^ watched, the animal takes 

 a few lame steps while at work, but the lameness disappears as sud- 

 dcnl}'' as it came and the driver doubts if the animal was really lame 

 at all. Later on the patient has a lame spell Avhich may last during a 

 greater part of the day, but the next morning it is gone; he leaves the 

 stable all right, but goes lame again during the daj'. In time he has 

 a severe attack of lameness, which may last for a weelc or more, when 

 a remission takes j^lace and it may be weeks or months before another 

 attack supervenes. Finally, he becomes constantly lame, and the 

 more lie is iised the greater the lameness. 



In the lameness from navicular disease the affected leg always takes 

 a short step, and the toe of the foot first strikes the ground, so that 

 the shoe is most worn at this point. If the iiatient is made to move 

 backwards the foot is set down with exceeding great care, and the 

 weight rests upon the affected leg but a moment. When exercised he 

 often stumbles, and if the road is rough he may fall on his knees. If 

 he is lame in both feet the gait is stilty, the shoulders seem stiff, and 

 if the patient is made to Avork he sweats profusely from the intense 

 pain. Early in the develoi)ment of the disease a careful examination 

 will reveal some increased heat in the heels and frog, particularly 

 after work; as the disease progresses this becomes more marked until 

 the whole foot is hot to the touch. . At the same time there is .an 

 increased sensibility of the foot, for the jiatient flinches from the per- 

 cussion of a hammer lightly applied to the frog and heels, or from the 

 pressure of the smith's pincers. The frog is generally shrunken, often 

 of a pale reddish color, and at times it is affected with thrush. If the 

 heels are pared awaj^ so that all the weight is received on the frog, or 

 if the same result is attained by the application of a bar shoe, the 

 animal is excessively lame. The muscles of the leg and shoulder 

 shrink away, and often tremble as the animal stands at rest. After 

 months of lameness the foot is found to be shrunken in its diameter 

 and apparently lengthened; the horn is dry and brittle and has lost 

 its natural gloss, while circular ridges, developed most tOAvard the 

 heels, cover the upper part of the hoof. When both feet are affected 

 the animal points first one foot then the other, and stands with the 

 hind feet well forward beneath the bodj' so as to relieve the fore feet 

 as much as possible from bearing weight. In old cases the wasting 

 of the muscles and the knuckling at the fetlock become so great that 

 the leg can not be straightened, and locomotion can scarcely be per- 

 formed. The disease generall}'^ makes a steady progress without 

 inclining to recovery — the remission of symptoms in the earlier stages 

 should not be interpreted as evidence that the i^rocess has terminated. 



