DISEASES OF THE FEET. 243 



action which has extended to it from the bone. Ultimately the tendon 

 may give way altogether. 



Symptoms. — Lameness may appear suddenly, and without any ap- 

 parent cause. It may disappear and after a time reappear, either in the 

 same or in the other foot, and thus go on for some time. This occurs as 

 a rule when the disease is due to rheumatism. In time the symptoms 

 become more marked, and, in most cases, the first is pointing of the foot 

 in the stable, also when at rest outside, followed by shortness in the step 

 and lameness. The foot and the horse may be examined, and nothing 

 wrong be found. Probably the next day the animal may be apparently 

 sound. But in the course of a few days the symptoms reappear andnsu- 

 ally are more marked than at first. 



Pointing in the stable is common with many horses as an act of rest, 

 or as a mere matter of habit. When, however, pointing arises either 

 from habit, or as an act of rest, the animal stands squarely upon one 

 fore-foot and allows the other to take a semi-flexed position in a careless, 

 lounging way; but he points two feet simultaneously; namely, one fore 

 and the other hind foot of the opposite side. In navicular disease, how- 

 ever, a fore-foot or feet only are pointed; there is no corresponding rest- 

 ing of the hind limb. 



The above signs may leads us to suspect navicular disease as the cause 

 of lameness. But the strongest indication of the disease lies in the ab- 

 sence of any observable cause, such as external injury or heat, sufficient 

 otherwise to account for the lameness. The fact of intermittent lame- 

 ness in the earlier stage, and of persistent lameness in the latter stage, 

 without any external symptoms sufficient to account for it, are the 

 strongest indications that the disease is in the navicular bone. 



The symptoms of lameness are evidently those of foot lameness. If 

 laminitis be present, there will be heat and tenderness, and the animal 

 will travel more or less on its heels. If a corn be the cause, its presence 

 is easily detected. In fact, in nearly every other form of disease, there 

 are external signs which will at once point to its cause. But in navicu- 

 lar disease, if we except occasional heat and tenderness in the hollow of 

 the heel, or redness of the frog and sole immediately below the navicular 

 bursa, there is no external sign. Even the redness of the frog and 

 sole, now and then met with, is not always to be depended upon as a sign 

 of navicular disease, as it may arise from external injury, such as tread- 

 ing on a stone, and may be superficial only. 



