There are two aspects you should pay most attention to when choosing your pet's food: the nutrient levels and the ingredients used. Your degu's diet should contain a MAXIMUM of 15% protein. For fat, it is up to 6%, with an ideal of 4%. For fibers, the ideal is 15% and more, but not less than 10%.

The degus are herbivores predisposed to diabetes, so it is extremely important to avoid foods that contains sugar. It is also important to give them hay at all times, since it is the major part of their diet.

As food for degus is scarce, it is quite common for people to give guinea pigs and/or chinchillas feed. Be careful never to give chinchilla seeds mixes to degus, as they contain dried fruit which can be harmful if offered daily.

You should NOT feed your degus with rabbit food or mixes, as these often contain a coccidiostatic compound which is harmful to degus. Coccidiostats are widely used in the animal feed industry as additives to treat and control coccidiosis infection. Some anti-coccidial drugs used, such as nitroimidazoles, have toxic properties and so this (coupled with the fact that most rabbit foods do not contain adequate levels of vitamins and minerals for degus) means that you should only not feed your rabbit food to your tastes. (Extract taken from Degutopia)