86 ESSENTIALS OF VETERINARY LAW 



or may not, have authority to order the killing. 

 If he has the authority the veterinarian acting 

 under such orders would be protected; but if he 

 does not have the authority the veterinarian acts 

 at his own peril. The veterinarian may know that 

 the killing is justifiable, but he must be prepared 

 to make proof of the fact which will convince the 

 court in the face of conflicting testimony. It is 

 ordinarily considered that a horse with a broken 

 leg is useless and without value, but this is not 

 always tnie. The writer once had a valuable colt 

 whose hook was broken squarely across. Never- 

 theless complete union occurred, and the horse did 

 many years of hard service, and was locally known 

 as a fast, long distance roadster, and he never 

 showed lameness. A mare, though lame from the 

 fracture of a small bone, was still of value for 

 breeding. In either case, had a veterinarian taken 

 the responsibility of killing the animal, he would 

 have assumed a liability for its loss. 



57. Burden of Proof. It is a general rule of 

 law that the one making a claim must prove it. 

 The fact that a man is practicing veterinary medi- 

 cine would be generally taken as an e^'idence of 

 his competency in that profession, aside from the 

 question of his right to practice. In his care of 

 the case the law presumes that he has used due 

 care and diligence, in accord with the state of the 

 science. He is not generally called upon to prove 

 that he is competent, but it becomes the duty of 

 one claiming to have been injured through his 

 malpractice or negligence to prove the fact to the 

 jury. When he has introduced evidence to show 

 negligence or malpractice the defendant has an 



