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We shall first speak of the causes to which navicular disease is to be 
attributed ; then of its symptoms and methods of detection, in this connection 
dealing with contracted foot; and, lastly, we shall review some of the various 
methods of treatment, unfortunately in many instances so futile. 
Hereditary influence, that potent predisposing factor in the causation of 
‘so many diseases, is often clearly traceable in navicular disease. The 
practical conclusion to be deduced from this fact is, that animals afflicted 
with this malady should not be used for breeding purposes. It has been 
-said, and we believe with good reason, that feet with high heels are more 
liable to navicular disease than open flat ones. When the soles are flat, 
there is necessarily more constant pressure on the frog, which, together with 
the structure it supports, is thus maintained in a more healthy state. It 
‘must be borne in mind that heredity is probably of influence not so much in 
predisposing animals to inflammation of the navicular bone, as in transmitting 
to the offspring that peculiar shape of foot which is especially liable to lead 
to such changes in this important structure. In any case the knowledge that 
heredity plays a great part in the production of this disease is of value, as 
indicating that affected animals should not be used for stud purposes. 
When we consider that the hind feet are very rarely affected with 
navicular disease, but that the fore feet are very commonly so diseased, one 
“naturally expects to find some cause which, though very rarely resulting in 
changes of this kind, is very potent in leading to disastrous lesions in the fore 
feet. What is the cause? It has often been noticed that this affection is far 
more commonly met with in horses used for quick work on hard roads, than 
among other animals. We naturally infer from these facts that navicular 
disease is largely dependent upon concussion or undue jarring, which 
necessarily affects the fore more than the hind feet, and is more violent and 
sustained in roadsters and hacks. 
The disease, it may be stated, often begins in the membrane lining the 
navicular joint, or in thé cartilage lining the surface of the bone, which is the 
‘spot where we should expect that the effects of constant and violent 
concussion would be especially liable to result in inflammatory changes. 
Among hunters and racers, navicular disease is not nearly so common ; 
for their work on softer ground does not cause this violent jarring. It is to 
the quick, long journeys made on the hard roads that this inflammation 
leading to such disastrous consequences is mainly due. Regarding these 
points Mr. Stewart long since wrote, “long journeys, performed quickly, will 
‘make almost any horse ‘groggy.’ Bad shoeing and want of proper care also 
help, but alone they never produce this affection. The animal must journey 
far and fast; but, if his feet be neglected, or the shoeing be bad, a slower 
pace and a shorter distance will produce the mischief.” 
As we might expect, navicular disease is almost unknown among cart- 
horses ; but they are more subject to laminitis than finer bred animals. In 
addition to the major causes of navicular disease, there are some minor ones 
we may shortly mention. Rheumatism is believed by some to be a 
cause of navicular disease, but we do not think this is ever the exciting factor. 
