AS TO SOUNDNESS. 8i 



LECTURE XI. 



NAVICULAR DISEASE. 



Gentlemen, — We now come to the subject of navi- 

 cular disease, vulgarly called " groggy lameness." 

 This is no place for much pathological reasoning, but 

 as very different explanations have been given as to both 

 the causes and nature of the affection, I feel bound 

 to say a few words about it, although I would like alto- 

 gether to evade the question. A.nd it would be not only 

 possible but reasonable for me to do so were the affec- 

 tion always apparent, as quittor or canker is apparent ; 

 but it is in many cases so concealed that we can only 

 arrive at the conclusion that we have navicular disease 

 by a process of exclusion, that is to say, when we find a 

 case of lameness of the fore extremity, and we fail to find 

 any physical defect we conclude that it must be 

 navicular disease which is causing the lameness, or, in 

 other words, we have to guide us. 



Negative Signs and Symptoms. 



Before going any further I will trespass on your time 

 by defining the difference— the vast difterence — between 



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