Opossums:

After a brief gestation period of about 13 days, Mother opossums give birth to up to twenty ½ inch long babies which make their way up to the mother's pouch. The tiny little animals are blind, hairless, and almost embryonic. Only a maximum of thirteen can survive, as they need to attach themselves to a nipple inside the pouch where they will remain attached for 60 days. At between 58-72 days of age their eyes will open and they will begin to venture outside the pouch. When they are about 3 months old, the babies will start eating small amounts of solid food but will continue to nurse. Once the young are eating solid food, they will run alongside their mother or ride on her back. Within a few weeks they will be weaned and will not depend on their mother.

Survival rate:

Young opossums that are removed from the pouch have a slim chance of survival. The very young that are not furred are nearly impossible to save. They are transparent with sealed mouths that have an opening at the end that attaches to the mother's nipples. The young opossums that have a little fur, but still have sealed mouths, have a better chance. And the babies that are mostly furred and the mouths are able to open, have a good chance of surviving.

Stabilization:

Warmth:

When first receiving any young opossums it is necessary to get their body temperature to normal (94-97 degrees F.) They should feel warm, not cool. If you have several, then the best method is to put them in a box with toweling on the bottom. For the very young babies, you can provide an artificial pouch by sewing three sides of a towel together. For warmth, place a heating pad under ½ of the box. It should be set on low with a towel folded between the box and the heating pad. If the young are unable to move to and from the heated side of the box, you will have to be extra careful monitoring the heat. Use a room thermometer placed near the young to help you keep an eye on the heat. Because the mother's pouch is very moist, it is important to supply humidity in the baby's environment. This may be accomplished by keeping a damp rag over part of the box.

Examination:

Check for any external injuries, head injuries, broken bones, and signs of internal injuries (blood from the nose or deep in the throat). Any of these injuries require attention from a veterinarian or wildlife rehabilitator. Small cuts and other minor injuries can be easily treated with guidance from a professional. Call our office for help.

Dehydration:

Most opossums come in dehydrated. Check to see if the skin "tents" when gently pinched between the shoulder blades. If the skin is slow to fall back into place, then the animal is probably dehydrated. Remember, the animal must first be warmed prior to any feeding or re-hydration. After the animal is warm, start feeding a re-hydrating fluid like Pedialyte every 15 minutes for the first hour. Once the animal is warm and re-hydrated, you may begin a regular feeding schedule.

Feeding:

Mix KMR (kitten milk replacer) or Esbilac according to the directions. For the first few feedings, add Pedialyte to the prepared formula at a ratio of 1:1, then start feeding the formula by itself unless diarrhea develops. If this happens, repeat the 1:1 ratio with Pedialyte for a few more feedings. Very young opossums with eyes still closed should be fed 1 cc via an eyedropper every two hours during the day with one or two feedings during the night.

Stimulation:

Stimulate young opossums after each feeding by using a soft cloth dampened with warm water. Gently stroke the genital area for 60 seconds, but do not be alarmed if the baby does not eliminate after each feeding. Usually after their eyes are open, the young will eliminate on their own. Until this happens, you should continue manual stimulation as needed.

Juveniles:

Opossums that can run around are ready to eat on their own and can be fed cut up pieces of fruit and some soaked, well-balanced, dry dog food in a dish. Also place some of the milk formula in a shallow dish that has bread to absorb it. Press the noses of the young in the bread a couple of times and they eventually will get the hang of it. As they grow and begin eating more solids try adding different foods, such as hard-boiled eggs, mealworms, vegetables, and insects.
Move the babies to an outdoor cage as soon as they are eating on their own so they can better acclimate.

Opossums should be released when they are about 10 inches long, not counting the tail. Try to release when the forecast calls for several days of fair weather. Release them after dark in an area free of dogs or cats and place food at the release site for a few days.

Also see

I Found A Baby Mammal - Now What?
How To Rescue Baby Mammal