LAMENESSES. 197 



there is much lameness. In young horses hasten the in- 

 evitable stiffness by a blister, firing, seton, or periosteot- 

 omy (dividing the periosteum, a very hard, elastic sub- 

 stance next to the bones and roots of the teeth). In old 

 horses sometimes incurable. The bone softens. 



BOG SPAVIN, 



When caused by inflammation of the joint, is a tense, 

 fluctuating swelling, accompanied by heat and pain. This 

 form constitutes unsoundness. It may be acute or chronic. 

 In the acute form the lameness is very great, with fever, 

 loss of condition, and the ability to put the foot to the 

 ground. It is apt to end in ulceration of the articular 



Fig. 14:. Bog Spavin, or distention of the chief synovial membrane of the 



hock joint. 



cartilage and partial stiffness of the joint. Some bog 

 spavins, however, are almost harmless, being mere dropsy 

 of the articulation (synovia for lubricating joints), arising 

 from some fault of conformation. 



Remedy. — Rest; in severe cases sling. High heeled 

 shoe. Foment when hot and tender. Cold water and re- 

 frigerants when inflammation abates. Spring truss in 

 young animals sometimes gives equable pressure. Counter- 

 irritittion encourages absorption. Firing-iron or seton in 

 chronic cases. 



THOROUGH-PIN OF THE HOCK 



Is a small, roundish or oval, membranous cavity on the 

 lower part of the thigh and upper and back part of the. 



