WEST OF ENGLAND VETERINARY MEDICAL ASSOCIATION. 77 
which in 1816, by Professor Sewell, has almost immortalised his 
name. 
Mr. Turner’s theory was that the disease commenced in the syno- 
vial membrane, and extended to the cartilage of the navicular bone 
and tendons. 
The late Professor Dick taught that the disease was the result of 
sprain of the tendon passing over the navicular bone, and that the 
fibres became lacerated and attenuated from friction over the 
roughened surface of the bone. 1 
These views have been generally received by the profession as 
correct, but I shall be able to prove to you that they are totally erro- 
neous. I will not occupy your time by relating a lot of symptoms 
which only indicate the disease in its advanced stages, but simply 
state that there are two symptoms which ought at all times to ex- 
cite suspicion, whether lameness exist or not; that is an upright 
pastern, either natural or the result of relaxation of the flexor 
tendon consequent upon work ; also pointing of the toe, although 
I have known horses point for years without becoming lame, and 
I have known other horses with confirmed navicular disease which 
never pointed. Contraction used to be considered the great cause, 
but it is now known to be only an effect of the foot not receiving 
its natural pressure from the ground. Feet may be naturally ob- 
long yet healthy ; or they may undergo a considerable change in 
shape, from the bad shoeing and stable management, without 
producing lameness. In fact there are numbers of horses with 
contracted feet which are perfectly sound. Such feet are, never- 
theless, more predisposed to take on diseases when subject to the 
exciting causes, than more perfectly shaped ones ; flat weak feet 
are also more liable to become affected with this disease as well 
as with laminitis ; it is, however, to be found in all kinds of feet. 
Horses with high action are also more liable from the greater 
amount of concussion produced. The temperature of the foot, as 
a rule, is increased after exertion in this disease ; but after stand- 
ing in the stable a short time it often becomes abnormally cold. 
No other part of a veterinary surgeon’s practice is tested so much 
as the opinions given in reference to lameness ; consequently it 
behoves him to avail himself of all the knowledge possible, to 
enable him to give correct opinions. In examining saddle horses 
as to soundness, I make a rule of riding them, which often enables 
me to detect faulty action, the result of navicular disease, when I 
have not been able to satisfy myself that it existed from merely 
seeing the horse trotted. 
When that system is not adopted, unsound horses are occasionally 
passed as sound ; and I make this statement without fear of its 
being disproved. 
The disease generally commences in one foot, and if not soon 
relieved, the other foot is very liable to become affected. There 
are predisposing causes, the greatest being hereditary ( i . e., ten- 
dency to a low form of inflammation in a particular tissue); inaction 
1 See ‘Veterinary Papers of Professor Dick,’ lately published. 
