Degus are sugar intolerant and are prone to diabetes. A commercial hamster/gerbil mix is therefore unsuitable and extra care needs to be taken to restrict sugar and avoid sugary treats.
Water should be offered in a bottle and constantly available. Glass bottles are best for degu, to avoid them damaging the plastic bottle. It is also good to use a metal clasp to attach the bottle. Your cage should be out of direct sunlight, but if you notice green algae in the bottles this must be cleaned with a bottle brush and you will need to reconsider where your cage is located.
A base mix of Chinchilla pellets (not mix as this may contain sugary dried fruits) together with a decent guinea pig mix is recommended.
Hay provides essential roughage in a degu's diet. This needs to be a good quality, such as Timothy Hay to provide enough fibre. Degu need constant access to hay, which can be supplied through a wooden or metal hay rack or scattered around the cage. You can mix alfalfa hay in as an extra treat but keep amounts low as this has high protein and calcium which could put strain on kidneys.
Avoid fresh fruit due to the sugar content but some vegetables are okay in small amounts, such as broccoli, carrot, green beans, lettuce and peas. Offer small amounts and vary the types of veg offered to reduce the risk of bloat. Basil, Mint and Parsley are some of the safe herbs for degu.
Sunflower seeds and pumpkin seeds, whole hazel or brazil nuts are good treats but must be offered in very small amounts due to the high fat and protein contents. Dried herb mixes sold in pet shops are often popular. If untreated with pesticides, fresh dandelions from your garden is a lovely treat for your pet.
Other good treats include rolled porridge oats, flaked corn/mazie and flaked peas and dried rosehips.