428 DISEASES OF THE HOESE'S FOOT 



bone, and characterized by changes in the form of the hoof 

 and persisting lameness. The disease is commonly noticed 

 in thoroughbreds or in horses of the lighter breeds, and is 

 but seldom observed in heavy cart animals. Usually it is 

 met with in one or both fore- feet. Although of extremely 

 rare occurrence, it has been noticed in the hind. 



History. — To English veterinarians appears to belong 

 the credit of discovering navicular disease. As early as 

 1752 we find one, Jeremiah Bridges, in * No Foot, No 

 Horse,' drawing attention to ' coffin-joint lameness,' and 

 advocating for its treatment setoning of the frog. It 

 appears, too, that Moorcroft, prior to his departure for 

 India in 1808, was acquainted with what was then known 

 as coffin-joint* lameness, having drawn attention to it in 

 1804 in a letter to Sir Edward Codrington.t In 1819 

 Moorcroft made it even plainer still that he was fully 

 acquainted with what we now know as navicular disease. 

 This we learn from a letter written by him to Sewell, in 

 which he laid claim to being the originator of neurectomy. 

 In this letter he says : 



' On dissecting feet affected with these lamenesses, the 

 flexor tendon was now and then observed to have been 

 broken, partially or entirely, but more commonly to have 

 been bruised and inflamed in its course under the navicular 

 or shuttle bone, or at its insertion into the bone of the 

 foot. Sometimes, although seldom, the navicular bone 

 itself has been found to have been fractured ; at others its 

 surface has been deprived of its usual coating, and studded 

 with projecting points or ridges of new growth, or exhibit- 

 ing superficial excavations more or less extensive.'* 



Pathohxjy and Point of Commencement of the Disease. — 

 The exact position in which the diseased process starts has 

 for a long time been a subject of discussion, and even now 

 it is doubtful whether the point has been definitely settled. 

 To mention but a few among many : We find Mr. Broad, of 

 Bath, strenuously insisting on the fact that the disease 



* The coffin- joint at this time inchided the navicular bursa, 

 t Percival's ' Hippopathology,' vol. iv., p. 132. \ Ibid. 



