We always want the best for our beloved pets, to make sure that if they get ill that they receive veterinary care as soon as possible, and one of the ways you can see if your guinea pigs are be becoming ill is to make a weight chart for them. Once every week or even maybe more often weigh your guinea pigs using for example a kitchen scale and if you see your guinea pigs weight drop suddenly this could be an indication that your pig is ill. Using this method you can get your pig the care it needs before it's too late.