Please help! I had 4 female guinea pigs who was around 18 months old and a few weeks back one of them died and we couldn't see why. W of the guinea pigs right from the start had been more bigger built and heavier and it was the biggest more dominant one that died. Now one of my other guinea pigs has lost lots of weight and is starting to loose fur around her neck area, nuggets are still left in the dish the next morning after feeding. But when I feed my guinea pig by hand, fresh vegetables she is eating them fine. She seems okay I'm her self and her eyes don't seem cloudy or weepy, does anyone know what is wrong?