DISEASES OF THE FEET. 225 



la ted strnctiire of the bone or the cartilage upon its surface. 

 As a result the tendon becomes lacerated and adherent to the 

 bone. The disease occurs in the fore feet, and is seen in saddle 

 horses more than any other class. In all its stages it constitutes 

 an unsoundness. The disease is always confined to the inferior 

 surface of the navicular bone and in connection with the tendon. 

 The great exciting cause of navicular disease is hard and fast 

 work, particularly on hard roads. A hereditary tendency is 

 also a cause. Certain breeds of horses are more or less subject 

 to navicular disease on account of faulty conformation, the dis- 

 ease being most frequently met with in horses having short, 

 upright pasterns and a pounding action. Allowing the animal 

 to be idle for a few days, feeding him highly in the mean time, 

 then taking him out for a severe ride or drive on a hard road 

 will cause it. 



I believe that, aside from concussion on hard roads, faulty 

 shoeing is the most prolific cause of navicular disease. The prac- 

 tice of the smith in removing the horn from the heels and soles 

 produces a contraction, which cause: an inflammation of the 

 joint. The great barriers to the collapse of the hoof at this part 

 are strong heels, bars, and soles. The majority of smiths re- 

 move a quantity of horn, in what they term "opening the heels," 

 which causes the foot to collapse and its sides approximate each 

 other too closely. 



I hold that contraction here is the cause„ and not the effect 

 of disease, as is the usual opinion. The smith frequently allows 

 the toe of the foot to become too longj, and applies a shoe, thick 

 and irregular at the toe, which by increasing the resistance of 

 the foot, while ini])hmtc(l ou the ground, throws an additional 

 strain on the tendon, which pas.ses under the navicular bone. 



Symptoms. — At first slight lameness, perhaps just after being 

 shod. There wdl be pointing of the foot. The examiner must 

 here not confound ]w)inting from lial)it or fatigue with the point- 

 ing of lameness. It may come on suddenly and be severe, or it 

 may come on gradually and be slight. A horse suffeiing from 

 15 



