My lil’ guinea pig was only 4 yrs. old. Perfectly healthy. I picked up a bag of Hartz natures gold guinea pig food at a local Store. A few days later my guinea pig was almost dead, she just laid down breathing was slow I knew she was dieing. An hour later she was gone. After thinking what in the heck was wrong I had just remembered that a few days earlier I had purchased new food. I do not know if this is the reason why this sudden death, but it sure made me think.