N A VICUL ARTHRITIS. 
183 
form of the hoof, we too frequently find we have gained nothing 
by it, because we have not restored the original structure of the 
parts contained within the hoof. Contraction of the hoof, in con- 
sequence of the internal parts being squeezed, produces inflam- 
mation of the laminae, and ossification of them. This causes the 
horse in galloping to avoid to his utmost coming down upon his 
heels or to tread upon hard ground, the concussion at such times 
being great from loss of elasticity in the laminae, so that the mo- 
ment he comes to work he falls lame. In nine cases out of ten 
of what are termed ‘ groggy’ or ‘ foundered’ horses, these parts, 
in consequence of chronic inflammation, become altered in struc- 
ture, effusion of lymph or bony matter taking place.” 
The above extract from the Professor’s Lectures, while it de- 
monstrates all absence of knowledge of disease in the navicular 
joint as connected with groggy lameness, shews the connexion 
existing in Coleman’s mind between such lameness and contraction 
of the hoof. Contraction, he says, by pressing upon the sensitive 
parts of the foot, “ produces inflammation of the laminse, and ossi- 
fication of them,” and this occasions groggy or foundered lame- 
ness. In another place he gives the causes of contraction, con- 
sisting, summarily, in want of pressure from above and from below. 
This leads us to an important part of our subject — the connexion 
between contraction and navicularthritis. 
Of contraction of the hoof there are two kinds : — one is a con- 
traction of the heels, called lateral contraction, the other contraction 
of the hoof from below upwards, or vertical contraction : by Mr. 
Turner called occult contraction. That of which Coleman is here 
speaking, and which, in fact, is meant when “ contraction” is talked 
about, is an anormal approximation of the heels — and sometimes 
quarters as well — of the hoof. The circumstance, so well-known 
and appreciated, of horses lame from navicularthritis, so far from 
having contracted feet, possessing commonly what are called 
“ open” or “ good” feet, clearly indicates that navicularthritis in 
nowise owes its existence to lateral contraction of the hoof. The 
fact of so many horses formerly being considered lame from con- 
traction, whereas, now-a-days, contraction is so little heeded that 
a case of lameness from it seems a rare occurrence, would appear 
to argue the contrary, viz. that navicularthritis must frequently 
beget contracted hoofs. We cannot believe, knowing what we 
do now, that the many cases treated in days gone by at the Vete- 
rinary College for “contraction,” were all lamenesses of that nature; 
on the contrary, we would almost take upon ourselves, at this re- 
mote period of time even, to pronounce that all were assuredly not. 
What were the exceptions, then ? Why, probably, cases of navi- 
cularthritis which from want of proper treatment had become in- 
