After discovering that one of my mice was diabetic I decided to mix my own mouse food. I've found that I benefit not only by controlling what's in the food, but the cost is considerably less than premixed food. Most of the ingredients average around $1.00 per pound, compared to $4.00 per pound for premixed food.
While mice are omnivores (they eat both plants and meat), grain comprises
much of their normal diet. The recipe reflects this and contains a number
of different grains. The basic diet includes the following ingredients
mixed in equal parts except where noted. Four mice receive 1 tablespoon
per day. I use mostly rolled grains because they seem to be preferred
to whole grains. I've noted that whole grains are often stored for times
of famine. If you notice a large amount of stored food you may be feeding
too much and should consider reducing the amount, particularly for overweight
You can substitute any of the rolled grains above with these grains for variety.
You can also add fish, cooked beans or rice, vegetables and fruit. I recommend starting with uncooked frozen peas and broccoli (both raw and cooked) and dandelion leaves in the spring and summer; apples are often well received. All vegetables and fruit should be given in small quantities, too much can cause diarrhea and dehydration. I would just watch for diarrhea and if it looks like a problem then cut back for a while. You can give fruit or vegetables 2 to 3 times a week. Because of the sugar content, most fruits should be restricted where diabetes is an issue.
I would leave out the sunflower and pumpkin seeds for overweight or diabetic mice. I would strictly control these and hand feed only a couple a days as treats.
For older mice or even mice that are underweight I've been feeding Flax Seed Oil in addition to the flax seed in their solid food. Flax seed oil really seems to help with joint problems in older mice that act a bit stiff and may have arthritis.
I also add vitamins and other nutritional supplements to their diet. I don't use any special animal vitamins; I just mix human vitamins in a solution to be added to their water. For generally healthy mice I recommend a good generic multi-vitamin. Other supplements can be added as needed.
The dosage listed is 1 human dose per day. Normally I would mix this with a quart of water as a concentrate for storage and then dilute that again at 1 ounce to a quart of water. You can crush any hard pills with a hammer. Put them in an envelope so they don't fly all over when crushed. Open any capsules and add the powder to the crushed pills. Use a blender to mix with a quart of water and store in the refrigerator, shake well before using. Mix 1 ounce of the concentrate with another quart of water for serving to the mice. This is good for mice that drink up to an ounce a day. I don't worry about mice that drink less; they are also getting vitamins from their solid diet so a little less doesn't hurt.
If you're dealing with a diabetic mouse you should adjust the dose to how much the mouse drinks. My one diabetic mouse, Athena, was drinking as much as 4 ounces a day. I managed to get her down to less than an ounce a day, but this required adjusting the dose as her consumption changed. For calculating dosage I figure an average human weighs about 150 lbs. (110 - 190 lbs.) and an average mouse weighs 1.5 oz. (1-2 oz.). There are 16 oz. to a pound, so you want to give your mouse about 1/1600 the human dose; every human dose provides 1600 mouse doses (150 lbs. * 16 oz. per lb. / 1.5 oz. per mouse). If your mice drink 1 oz. a day each, you would want to dissolve 1 human dose into 1600 oz. water. It's more likely that 4 mice drink 1/2 oz. per day or 1/8 oz. each per day. At that rate you would mix 1 human dose to 1600/8 oz. water or 200 oz. water (about 3 gallons or 12 quarts). So if you mix 1 human dose into 1 quart of water for storage and then dilute at 12 to 1 you would get the correct mouse dose. Refrigerate the stored mixture. Of course mice don't always drink the same amount every day and some mice drink more than others. Unless you have a problem like one mouse drinking a lot, I would just take an average on all the mice together. You will need to monitor your mice for average water consumption.