They have to make sure that they are giving the correct amount of medicine to the dog according to its weight. They have to balnce out their checkbook, just like anyone else. If you have kids, you have to work out your finaces for ballet class and pay for those soccer jerseys. You would have to buy food. Plus, if someone wanted an estimate on how much surgery would cost them, you'd have to be able to add up the expences. ~Minicooper Out!