In all his stock raising, as in most other matters, Washington was greatly hampered by the carelessness of his overseers and slaves. It is notorious that free negroes will often forget or fail to water and feed their own horses, and it may easily be believed that when not influenced by fear, slaves would neglect the stock of their master. Among the General's papers I have found a list of the animals that died upon his Mount Vernon estate from April 16, 1789, to December 25, 1790. In that period of about twenty months he lost thirty-three horses, thirty-two cattle and sixty-five sheep! Considering the number of stock he had, a fifth of that loss would have been excessive. During most of the period he was away from home looking after the affairs of the nation and in his absence his own affairs suffered. Hardly a report of his manager did not contain some bad news. Thus one of January, 1791, states that "the Young black Brood Mare, with a long tail, which Came from Pennsylvania, said to be four Years old next spring ... was found with her thigh broke quite in two." This happened on the Mansion House farm. On another farm a sheep was reported to have been killed by dogs while a second had died suddenly, perhaps from eating some poisonous plant. Dogs, in fact, constituted an ever present menace to the sheep and it was only by constant watchfulness that the owner kept his negroes from overrunning the place with worthless curs. In 1792 he wrote to his manager: "I not only approve of your killing those Dogs which have been the occasion of the late loss, & of thinning the Plantations of others, but give it as a positive order that after saying what dog, or dogs shall remain, if any negro presumes under any pretence whatsoever, to preserve, or bring one into the family, that he shall be severely punished, and the dog hanged.--I was obliged to adopt this practice whilst I resided at home, and from the same motive, that is for the preservation of my Sheep and Hogs.... It is not for any good purpose Negroes raise, and keep dogs; but to aid them in their night robberies; for it is astonishing to see the command under which the dogs are." After the Revolution, in imitation of English farmers, he made use of hurdles in pasturing sheep and milk cows. Thereby he secured more even distribution of the manure, which was one of his main objects in raising stock.