Aquariums with screen tops have inadequate ventilation leading to many respiratory infections in small rodents. Screen tops on reptile housing does not allow the enclosure to stay warm enough. Habitrail enclosures also have improper ventilation. Cedar chips are not absorbent and are very abrasive. The aromatic cedar oils responsible for the aroma also coat the animal causing respiratory and liver dysfunction.
Diets containing seeds are very detrimental.
They contain no vitamins, minerals or protein. A proper diet consists of rodent 'blocks'. See husbandry hand-outs for details. Too many pellets cause obesity and urinary tract problems. Guinea pigs require Vitamin C in their diet.