I don't even want to think about what goes into house training a buffalo. Instead of a rolled up newspaper you'd need a 2 x 4.
NPR had a radio essay a couple of years ago about a couple that kept a horse as a house pet. It slept in their room and ate meals with them in the kitchen. They had to substantially upgrade their floors to hold the weight. It was actually house trained and would go to the door when it wanted to go out and take care of business.
My exwife has 4 English Mastiffs totaling about 1000 lbs. which is a heck of a lot of dog for one little house. I'd send her the link for this image but we are on pretty good terms now and I wouldn't want to screw it up!