DISEASES OF HORSES 229 



subdue the inflammation, abort the soreness, absorb the excess of se- 

 cretion, strengthen the walls of the sac, and finally cause the wind- 

 galls to disappear, provided the animal is not too quickly returned 

 to labor and exposed to the same factors that occasioned them at first. 



But if the inflammation has become chronic, and the enlarge- 

 ment has been of considerable duration, the negative course will be 

 the wiser one. If any benefit results from treatment it will be of only 

 a transient kind, the dilatation returning when the patient is again 

 subjected to labor, and it will be a fortunate circumstance if inflam- 

 mation has not supervened. 



But notwithstanding the generally benignant nature of the 

 swelling there are exceptional cases, usually when it is probably 

 undergoing certain pathological changes, which may result in lame- 

 ness and disable the animal, in which case surgical treatment will be 

 indicated, especially if repeated blisters have failed to improve the 

 symptoms. Line firing is then a pre-eminent suggestion, and many 

 a useful life has received a new lease as the result of this operation 

 timely performed. Another method of firing, which consists in 

 emptying the sac by means of punctures through and through, made 

 with a red-hot needle or wire, and the subsequent injection into the 

 cavity of certain irritating and alterative compounds, designed to 

 effect its closure by exciting adhesive inflammation, such as tincture 

 of iodine, may be commended. But they are all too active and en- 

 ergetic in their effects and require too much special attention and 

 intelligent management to be trusted to any hands other than those 

 of an expert veterinarian. 



BLOOD SPAVIN, BOG SPAVIN, AND THOROUGHPIN. 



The blood spavin is situated in front and to the inside of the 

 hock and is merely a varicose or dilated condition of the saphena 

 vein. It occurs directly over the point where the bog spavin is found, 

 and has thus been frequently confused with the latter. The compli- 

 cated arrangement of the hock joint, and the powerful tendons 

 which pass on the posterior part, are lubricated with the product of 

 secretion from one tendinous synovia! and several articular synovial 

 sacs. A large articular sac contributes to the lubrication of the 

 shank bone and one of the bones of the hock. The tendinous sac 

 lies back of the articulation itself and extends upward and down- 

 ward in the groove of that joint through which the flexor tendons 

 slide. The dilatation of this articular synovial sac is what is denomi- 

 nated bog spavin, the term thoroughpin being applied to the dilata- 

 tion of the tendinous capsule. 



The bog spavin is a round, smooth, well-defined, fluctuating 

 tumor situated in front and a little inward of the hock. On pressure 

 it disappears at this point to reappear on the outside and just behind 

 the hock. If pressed to the front from the outside it will then appear 

 on the inside of the hock. On its outer surface it presents a vein 

 which is quite prominent, running from below upward, and it is to 

 the preternatural dilation of this blood vessel that the term blood 

 spavin is applied. The thoroughpin is found at the back and on 

 the top of the hock in that part known as the hollows, immediately 



