The mouse is an “omnivore” mammal par excellence and is able to obtain nutriment from just about anything organic that it finds in nature. For a question of practicality, the diet of the pet mouse is often based on specifically formulated food pellets which contain approximately 16-18% of protein and 4-5% of fats. A mouse usually eats about 4-5 grams a day, although it is wise to provide the food ad libitum in order that each animal can self-regulate its own intake in relation to its physiological needs. The food pellets are usually large (up to 1 cm in diameter) (Fig. 1) and are composed of various raw materials including crushed corn, barley, wheat, soy extracts, dried alfalfa, meat meal, fish meal as well as powdered milk whey and brewer’s yeast. Other commercial diets are based on seeds (corn, oats, wheat, millet, barley and sunflower) (Fig. 2) as well as flakes and kibble. Care should be taken not to give the animals too many sunflower seeds which, although being very appetising, contain very little calcium and are too rich in fats and cholesterol. Other recommended foods are fruit and vegetables in small amounts, although limiting dried fruit: this should be supplied with moderation and with its shell in order to help attrition of the teeth. If desired, a portion of light kibble for dogs can be added a couple of times a week. Dry bread and biscuits are greatly enjoyed but must be considered as treats and always given in small amounts. Chocolate should always be avoided.
The mouse regularly eats its own faeces from which it recovers many nutrients that would otherwise be lost. The average daily intake of water is about 6-7 ml although the amount can vary greatly depending on the season and the intake of dry or wet food: as for food, water should be freely available. The feeders are usually bowls or small containers rather than “hoppers” while the best water dispenser is a small bottle with a metal spout (the extremely common bottles used for other rodents are fine) (Figs. 3 and 4) rather than a water bowl which would be inappropriately used as a bath or, worse still, would be overturned. In the case of a diet of food pellets, a specifically designed rack can be used to minimise waste (Fig. 5).
