340 DISEASES OF THE FEET. 



definite period reappear either in the same foot or its fellow. 

 The rheumatoid form is thus manifested. 2d. By a slow and 

 insidious process in one or both feet, and this is the most 

 common form; the first noticeable sign being pointing of the 

 foot, succeeded after a time by "shortness of the step" and 

 lameness, which may be of a transitory character. For example, 

 " a horse may quit the stable apparently sound, and it very often 

 happens that the rider or driver may fancy that the horse now 

 and then goes lame. The foot is examined, and nothing found, 

 and next morning he may seem all right again. The next 

 journey perhaps, or rapid work, brings back the lameness, which 

 after a little rest and a poultice to the foot disappears again ; he 

 may perhaps favour it a little, but there is nothing of conse- 

 quence the matter, but in the end, if the fast work is continued, 

 the case becomes confirmed." — (Percivall.) 



The diagnostic signs of navicular lameness are — 1st. Negative ; 

 2d. Positive. (1.) The negative signs are the absence of injury 

 to any part of the limb, and of any apparent disease. These are 

 diagnostic of foot lameness, and are of importance, as they limit 

 the seat of the disease to the foot. This region must now be 

 explored, and lameness in the foot may exist from various 

 causes, but in each variety the signs are different. If laminitis 

 be present, there will be heat, tenderness, &c. If a corn be the 

 cause, its presence is easily detected; in fact, in nearly every 

 other form, except navicular arthritis, there will be some appre- 

 ciable sign ; but in the disease in question — if we except occa- 

 sional heat and tenderness in the hollow of the heel, or redness 

 of the frog and sole immediately below the navicular bursa — 

 there will be no apparent sign. The redness of the frog and 

 sole, now and then met with, is very characteristic when really 

 due to navicular disease ; but it is not always to be depended 

 upon, as it may arise from external injury, such as treading 

 upon a stone, and may be superficial only. Pointing of the foot 

 or feet, although a most valuable adjunct to a correct conclusion 

 when taken along with other signs, is of itself quite insufficient 

 to mark the seat of the lameness ; for it may depend upon other 

 causes, such as splint, sprain, ring-bone, &c. ; or an animal may 

 point and be perfectly free from any unsoundness. This " point- 

 ing" may be a mere habit, or a sign of fatigue. In such 

 instances, however, it differs in its character from the pointing 



