Naviatlar Disease. 125 



pressure is imposed upon the navicular bone. 

 The coffin-bone undergoes more change in physi- 

 cal formation and far more rapidly than occurs in 

 other bones, I may say of any animal, for the 

 reason that no bone is placed under so many 

 complications of influence and misapplied art and 

 exertion combined. The semiluna crest and the 

 normal asperities of the coffin-bone become 

 absorbed under the influence prevalent by which 

 the attacking processes for the tendon, the planta 

 band and the frog, are all weakened and their 

 positions become altered. The navicular-bone is 

 more and more called upon to bear pressure when 

 its normal bulk would lack space, therefore 

 absorption of its substance takes place from 

 within, until at length the outer surface breaks 

 down; being always on its lower and posterior 

 surface where the ulcerated apertures one or more 

 are seen, whence lymph issuing becomes attached 

 to the tendon, by which eflbrt of nature the 

 structure becomes in some measure fixed to- 

 gether, and the otherwise unsupportable friction 

 is diminished. Tor the treatment of this disease 

 I repeat the words of Professor Gamgee, in a 

 lecture upon this subject delivered by him at the 

 New College of Veterinary Surgeons. He said, 

 '^ Our treatment is all of a prophylactic kind ; 

 firstly preventive measures are the great resource, 

 the taking care of the stable ere the steed is lost 

 is our watchword ; but cases will make their 

 appearance, and although not one case in ten of 

 those pronounced to be navicular disease are of 

 that type, yet in various stages of progress cases 



