Things You'll Need
- Human infant formula (soy, powdered)
- 1 cc veterinary syringe
- Gram scale
- Distilled water
- IV catheter
- Small jar lid
- Flat magnet
Instructions
Preparing Formula
Sterilize the catheter and syringe in boiling water. Cut an IV catheter into a piece several inches long. Re-sterilize the catheter and syringe daily.
Weigh the rat on a gram scale. Multiply its weight in grams by 0.05; this is how many cubic centimeters of formula it should be given at each feeding (for example, an 8.2 g rat should be given .41 cc of formula at each feeding).
Heat water to 105 F. Add 1 part of the powdered formula to 4 parts of water for the first feeding. Stir thoroughly and allow the formula to cool to approximately 100 F.
Draw the mixed formula into the syringe. Fit the catheter onto the end of the syringe.
Initial Feeding
Ensure that the temperature of the formula is still warm, not hot, and reheat it to around 100 F, if necessary. Warm your hands with hot water to avoid shocking the infant when you handle it. Carefully but firmly pick up the baby rat and hold it upright (head up, tail down), supporting the neck with your fingers.
Introduce the end of the catheter into the rat's mouth and carefully squeeze several drops of formula into its mouth. Once the rat begins to suck at the catheter, slowly squeeze on the syringe and feed as necessary.
Remain alert to aspiration; introducing too much formula too quickly can result in the infant inhaling it instead of swallowing. If formula drips from its nostrils, stop feeding and wipe it away. Do not continue feeding until it has cleared its nasal cavity of formula.
Regular Feeding
Reduce the water to powder ratio of the formula by half a part of water on each successive feeding (3.5 parts of water to 1 part formula, then 3 parts water to 1 part formula, etc.) until at a ratio of 2 parts water to 1 part formula is reached. Revert to 3.5 parts water to 1 part formula if diarrhea or bloating occurs.
Feed the newborn rat every three to four hours in the day during the rat's first week, and once at night. Feed every four to five hours during weeks two and three, including night feeding if necessary.
Begin dish feeding after the rat's eyes have been open for several days. Place a small jar lid on a flat magnet in the rat's enclosure. Introduce formula to the dish after a feeding to allow the rat to examine it. Monitor the rat to see if it consumes the formula. Switch from hand feeding to dish feeding once the rat begins to drink from the dish, and offer fresh formula three to four times a day. Supplement with small pieces of fruit, vegetables and rat blocks.
Wean completely at four weeks, eliminating formula and giving exclusively solid food.