DISEASES OF THE HOKSE. 333 



toms, treatment, etc., are our reasons for treating under a single head 

 the ailments we have grouped together in the present section. 



Cause.- — The great, comprehensive, common cause of, sometimes 

 permanent, sometimes only transient, disability of the horse is 

 external traumatism. 



Blows, bruises, hurts by nearly every known form of violence, falls, 

 kicks, lacerations, punctures — we may add compulsorj^ speed in racing 

 and cruel overloading of draft animals — cover the entire ground of 

 causation of the diseases and injuries of the joints now receiving our 

 consideration. 



In one case, a working horse making a misstep stumbles, and full- 

 ing on his knees receives a hurt, variously severe, from a mere abra- 

 sion of the skin to a laceration, a division of the tegument, a slough, 

 mortification, and the escape of the synovial fluid, with or without 

 exposure of the bones and their articular cartilages. 



In another case, an animal, from one cause or another, perhaps an 

 impatient temper, has formed the habit of striking or pawing his 

 manger with his fore feet until inflammation of the kneejoint is 

 induced, first as a little swelling, diffused, painless; then as a perios- 

 titis of the bones of the knee; later as bon}^ deposits, then lameness, 

 and finally the implication of the joint, with all the various sequels of 

 chronic inflammation of the kneejoint. 



In another case, a horse has received a blow with a fork from a 

 careless hostler on or near a joint, or has been kicked by a stable 

 companion, with the result of a punctured wound, at first mild-look- 

 ing, painless, apparently without inflammation, and not yet causing 

 lameness, but which, in a few hours, or it maj^ be only after a few days, 

 becomes excessively painful, grows worse, the entirQ joint swells, 

 presently discharges, and at last a case of suppurative synovitis is 

 presented, with perhaps disease of the joint proper, and arthritis as 

 a climax. The S3'mptoms of articular injuries vary not only in the 

 degrees of the hurt, but in the nature of the lesion. 



Or the condition of oroken hnees^ resulting as we have said, ma}^ 

 have for its starting point a mere abrasion of the skin — a scratch, 

 apparently, which disappears without a gesulting scar. The injury 

 ma}^, however, have been more severe, the blow heavier, the fall aggra- 

 vated by occurring upon an irregular surface, or sharp or rough object, 

 with tearing or cutting of the skin, and this laceration may remain. 

 A more serious case than the first is now brought to our notice. 



Another time, immediately following the accident, or possibl}- as 

 a sequel of the traumatism, the tendinous sacs" may be opened, with 

 the escape of the synovia; or worse, the tendons which pass in front 

 of the knee are torn, the inflammation spreads, the joint and leg 

 are swollen, the animal is becoming ver}^ lame; synovitis has set in. 

 With this the danger becomes ver^^ great, for soon suppuration v;ill be 



