DISEASES OF HORSES 215 



tion of the seat of trouble, but he must carefully refrain from the 

 adoption of a hasty conclusion, and, above all, assure himself that he 

 has not failed to make the foot, of all the organs of the horse the 

 most liable to injury and lesion, the subject of the most thorough 

 and minute examination of all the parts which compose the suffering 

 extremity. 



The greater liability of the foot than of any other part of the 

 extremities to injury from casualties, natural to its situation and use, 

 should always suggest the beginning of an inquiry, especially in an 

 obscure case of lameness at that point. Indeed the lameness may 

 have an apparent location elsewhere when that is the true seat of 

 the trouble, and the surgeon who, while examining his lame patient, 

 discovers a ringbone, and satisfying himself that he has encountered 

 the cause of the disordered action suspends his investigation without 

 subjecting the foot to a close scrutiny, may deeply regret his neglect 

 and inadvertence at a later day, when regrets will avail nothing 

 toward remedying the irreparable injury which has ensued upon his 

 partial method of exploration. But, as in human pathological ex- 

 perience, there are instances when inscrutable diseases will deliver 

 their fatal messages while leaving no mark and making no sign by 

 which they might be identified and classified, so it will happen that 

 in the humbler animals the onset and progress of mysterious and un- 

 recognizable ailments will at times baffle the most skilled veterinar- 

 ian, and leave our burden-bearing servants to succumb to the inevit- 

 able, and suffer and perish in unrelieved distress. 



DISEASES OF BONES. 



Periostitis, Ostitis, and Exostosis. From the closeness and in- 

 timacy of the connection existing between the two principal elements 

 of the bony structure while in health, it frequently becomes exceed- 

 ingly difficult, when a state of disease has supervened, to discrim- 

 inate accurately as to the part primarily affected, and to determine 

 positively whether the periosteum or the body of the bone is orig- 

 inally implicated. Yet a knowledge of the fact is often of the first 

 importance, in order to secure a favorable result from the treatment 

 to be instituted. It is, however, quite evident that in a majority of 

 instances the bony growths which so frequently appear on the sur- 

 face of their structure, to which the general term of exostosis is ap- 

 plied, have had their origin in an inflammation of the periosteum, 

 or enveloping membrane, and known as periostitis. However this 

 may be, we have as a frequent result, sometimes on the body of the 

 bone, sometimes at the extremities, and sometimes involving the ar- 

 ticulation itself, certain bony growths, or exostosas, known otherwise 

 by the term splint, ringbone, and spavin, all of which, in an im- 

 portant sense, may be finally referred to the periosteum as their nu- 

 trient source and support, at least after their formation, if not for 

 their incipient existence. 



Cause. It is certain that inflammation of the periosteum is 

 frequently referable to wounds and bruises caused by external agen- 

 cies, and it is also true that it may possibly result from the spreading 

 inflammation of surrounding diseased tissues, but in any case the 



