304 WINDGALL OF THE TENDO ACHILLIS. 



the swellings, and this we now know to be through the interven- 

 tion of the hock-joint. 



Thorough-pins, chronic in their nature, existent in hocks under- 

 going, or that have undergone, great and continued stress from 

 work, with time experience changes, which, if not alike in degree 

 or intensity, are similar to those we have detected in bog spavin. 

 Old thorough-pins, under circumstances stated, lose their pliancy of 

 feel, their elasticity, and their fluctuation ; they acquire a substan- 

 tiality they never possessed before, and are evidently from inward 

 deposition approaching a state of consolidation. To what extent 

 such changes of structure have gone, or may go, we must ask those 

 who have had opportunities of dissecting thorough-pinned hocks 

 advanced in disease to kindly inform us. 



Of Lameness from pure Thorough-pin we know of no 

 example on record ; 



Treatment, therefore, will hardly be called for. 



WiNDGALL OF THE TeNDO ACHILLIS. 



Dearth of names for diseases compels us on occasions, as in the 

 present instance, to substitute some paraphrase designative of their 

 seat or nature, or of some other striking attribute, for an appropriate 

 appellation. The French call this disease vessignon soufflte ; and 

 it has something the appearance of an inflated bladder, running 

 along the '* hamstrings" or united tendons of the gastrocnemii 

 muscles. These tendons are enveloped in a cellular sheath, and 

 between is a thecal cavity or sort of bursa, lined with synovial 

 membrane, and lubricated by synovial fluid ; and this interspace 

 or cavity it is which is the seat of the disease now under our 

 consideration : it consisting, like windgall, in an undue secretion 

 and collection of the synovial fluid. 



Windgall of the Tendo Achillis is comparatively rare. 

 Now and then it is complicated with thorough-pin, but is rarely 

 or never an accompaniment of capped hock. 



The Causes of this tumefaction being some extraordinary or 

 unexpected tug, stretch, or strain of the hamstrings, and partaking 



