428 DISEASES OF THE HORSE’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.’ t 
Pathology 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 included the navicular bursa. 
{ Percival’s ‘ Hippopathology,’ vol. iv., p. 132. { Ibid. 
