OSSIFICATION OF THE LATERAL CARTILAGES. 293 



Rarely, indeed, is navicular-joint lameness found existing in 

 feet that have open heels and elastic frogs. If from any cause 

 these frogs lose their mois.ture, they also lose their elasticity, 

 and the foot therefore strikes the ground with a jar ; inflamma- 

 tion of a chronic character sets in ; the synovia (joint-oil) be- 

 comes absorbed ; and caries of the bones is established, which 

 destroys their articular surfaces and causes excessive lameness. 

 Occasionally, owing to some new injury, acute inflammation 

 sets in, causing new depositions of bone to be thrown out, and 

 uniting the three bones together ; which union is called anchy- 

 losis. This condition may be known by stiffness, and the 

 animal walking upon the toe. 



The symptoms of this disease have been confounded with 

 those of another disease of the foot, which has been discovered 

 by recent investigations. The horse is found to go lame upon 

 coming out of the stable, which wears off after traveling some 

 distance; one foot is observed in advance of the other when 

 the animal is at rest ; as the disease advances, the lameness 

 becomes more frequent, until at last it is permanent. Ya^us 

 kinds of treatment have been resorted to, but with little 

 success, such as blistering, firing, etc. Of late years, the frog 

 seton has been introduced with very decided benefit. Should 

 this, too, fail, there is no hope but in the operation of nerving, 

 which should only be performed in certain cases mentioned 

 under the head of neurotomy. 



OSSIFICATION OF THE IiATERAL CARTILAGES. 



This is a transformation to bone of two projections of car- 

 tilage, or gristle, springing from each side of the coffin bone 

 posteriorly, and known as the lateral cartilages. This disease 



