HORSES. 



11 



Fifrurc 2. 



be developed from similar exciting causes or from an inherited 

 constitutionality. 



Every bone in the normal condition of nutrition grows 

 large by the deposition of new material upon its external sur- 

 face through the instrumentality of the periosteum. And 



any agency which will increase the 

 flow of blood to that part and thus 

 unduly excite the action of this mem- 

 brane, will cause this excessive and 

 morbid production of bone. But 

 there is evidently a certain peculiar- 

 ity in the general nutrition of the 

 body, favorable to the production of 

 this disease ; for it is often seen, 

 even fearfully developed, in the colt 

 at an early age, where no external 

 or exciting cause could have played 

 its part. Such a condition of the 

 system might well be termed, in the 

 language of pathology, an exosfosi- 

 cat diathesis. 



Though every bone in the skeletal 

 frame-work of the horse is liable to 

 an attack of exostosis, yet the joints 

 are the most frequently the seat 



"Chest Founder." 



of this disease. In 

 usually involves the 



rheumatism, or '' founder. 



which 

 periosteum of the bones of the 

 chest, you will occasionally find, upon post-mortem ex- 

 amination, that the lower end of the ribs and their appendages 

 are affected with this same malady. At Figure 2 will be seen 

 a case of ''chest-founder," so called, in which the first and 

 second ribs of the right side are firmly grown together, and 

 are attached by a bony union to the first rib of the opposite 

 side. This specimen was taken from a horse thirty years of 

 age, which was noted for its general usefulness, yet we imagine 

 that this creature must have suffered in its respiratory func- 

 tions, inasmuch as the anterior part of the thorax, or chest, 

 was a solid bone hoop. May not this form of the disease ac- 



