Chapter IX. 



BURSAL ENLARGEMENTS. 



It is usual to classify all swellings which have their 

 origin in injuries resulting in distensions of the burs^ 

 due to an increased secretion of synovia, commonly 

 called joint-oil, under the above heading. 



The true joints, some ligaments, and parts of all 

 tendons are enclosed by sheaths, or bursae, which are 

 lined by a membrane called the synovial membrane. 

 This secretes the joint-oil. Any injury to the joints 

 arising from overwork, sprains, Arc, excites the synovial 

 membrane to secrete more than the normal quantity of 

 fluid ; consequently the sheaths or bursae become dis- 

 tended, and we get the enlargements, to which distinc- 

 tive names are applied according to where they appear. 



BOG SPAVIN is the name given to the trouble when 

 it appears in the region of the hock joint, the front and 

 inner part of which will be distinctly puffy both to the 

 eye and to the touch. It may or may not cause lame- 

 ness, according to its origin. If it does, chronic in- 

 flammation is to be suspected, which is, of course, 

 serious. 



