365 



Various experiments in the line of treatment have been instituted, 

 but none have been crowned with satisfactory results. We incline to 

 the opinion that some undesignated disease of the hock is responsible 

 for it, and believe that in tlie present state of knowledge the best i)re- 

 scription that can be devised is the safe and economical one of rest, a 

 long rest in a i^asture, where unmolested nature shall be permitted to 

 bring about any necessary change that may be appropriate to the case. 

 Whatever other treatment it may be considered wise to undertake 

 must be of a widely different character, and must be determined upon 

 by those whose chosen and appropriate sphere is the domain of oj^er- 

 ative surgery. 



Embolisms. — There are certain forms of lameness which are very 

 peculiar in their manifestation, and which to the non-professional mind 

 must appear to belong rather to the domain of mystery or theorj" than 

 to be subjects of experimental and definite knowledge. Yet they are 

 none the less susceptible of demonstration and positive knowledge 

 than manj^ facts which, plain and familiar to the general comprehen- 

 sion now, were once ranked among things occult and unsearchable. 

 An embolism, considered as a cause of lameness, may find a i)lace 

 among these understood mysteries. 



Under certain peculiar conditions of inflammation of the blood ves- 

 sels, clots of blood are sometimes formed in the arteries and find their 

 way in the general circulation. At first, while very small, or suffi- 

 cientl}' so to pass from one vessel to another, they move from a small 

 vessel to a larger, and from that to one still larger, constantly increas- 

 ing in size until at some given point, from their inability to enter 

 smaller vessels, their movement is finally arrested. The artery is thus 

 effectually dammed, and the clot in a short time cuts off completely 

 the supply of blood from the parts beyond. This is the embolism, and 

 it often gives rise to sudden and excessive lameness of a very painful 

 character. 



Embolisms may form in any of the arteries of the bodj', and doubt- 

 less have been the cause of many cases of lameness which could never 

 be accounted for. If they exist in small arteries their diagnosis will 

 probably fail to be made out with certainty, but when situated in the 

 larger trunks a strong suspicion of their presence may be excited. In 

 some cases they may even be recognized with positive accuracy, as 

 when the vessels Avhich supply the posterior extremities are affected 

 by the blocking up of the posterior aorta or its ramifications. 



The existence of embolisms of the arteries of the hind leg may 

 always be suspected when the following history is known: The gen- 

 eral health of the animal is good, but symptoms of lameness in one 

 of the legs have been developed, becoming more marked as he is 

 worked, and especially when driven at a fast gait. But the disturb- 

 ance is not permanent, and the lameness disapi^ears. almost imme- 

 diately upon his being permitted to rest. There is an increase of the 



