Wildlife Rehabilitation - Care for Orphaned or Injured Wild Animals

What to do with a baby mouse I found?

My cat just caught a mouse (or rat) and it’s still alive! This is very important: If you cat has caught a mouse, you are usually better off letting nature take its course. Cats, even house cats, are carnivorous creatures, something we tend to forget as we pile up the dry kitty kibble. Animals eat other animals. There is nothing wrong with this scenario; it’s just how nature works. That being said, if you have already taken the mouse away from your cat, that mouse needs IMMEDIATE antibiotic therapy administered by a veterinarian. Due to the bacteria in a cat’s mouth, any bite wounds on a small animal can cause death by scepticemia. Timely treatment is vital.

Babies! If you have just stumbled upon a nest of baby mice, generally found after the mother has been killed by a trap or pet, there are some things you can do before your wildlife rehabilitator arrives. Obtain a small box and line it with loose rags. Make sure the cloth strips have no uncut fibers that could tangle around the baby’s legs. A heating pad or warm bottle of rice should be placed in contact with the abandoned rodent. Watch the temperature! Something tolerable to the touch of your hand may be too hot for a newborn mouse. Eighty to a hundred degrees is the ideal temperature for a mouse nest.

To find a rodent rehabber in your area, click on my nationwide directory of wildlife rehabbers or do an online search for one in your area. In the meantime, you can still care for the rodent as advised below.

If the mice are under two weeks of age, their eyes will not yet be open. At this stage, mice and rats need to be fed every two hours even through the night. These two-hour interval feedings will last for the full two weeks until the baby’s eyes are open. If your baby mice have just recently lost their mother within a few hours, you can forgo the need to rehydrate them prior to formula feeding; however, it is always advisable to assume there is some degree of dehydration. Baby mice are insanely small, so you will need a very small syringe to administer Pedialyte (or any other non-flavored electrolyte supplement). Pet stores often carry special feeding syringes with a fine, curved tip. You cannot feed mice less than two weeks of age with an eye dropper. Their mouths are so small, the liquid must be slowly given directly into the mouth. While doing this, you must be very careful not to push too much electrolyte fluid in too quickly or the baby will aspirate and drown or develop pneumonia.

How can I tell if aspiration has occurred? You can tell when a baby rodent has aspirated if a fluid bubble appears out of the nose while feeding. If this happens, immediately turn the baby upside down to prevent any more fluid from draining into the lungs. If such a young mouse has aspirated, it will be unlikely to survive. You can prevent most cases of aspiration by holding the baby mouse vertical while feeding. Wild animals should never been held on their backs like human infants.

Ideally, a wildlife rehabilitator will take over the feeding of the baby mouse before you have to get involved with mixing actual formula or burning the midnight oil feeding the little guys. A rehabilitator will administer kitten milk replacer, diluted twice the regular consistency, every two hours until the baby rodent’s eyes open. Kitten milk replacer must be watered down because the infant’s throats are so small, regular formula is too dense to pass into the stomach without causing choking.

Unlike with opossums, baby rats and mice are often too small to initiate urination and defecation with a damp towel. A warm, wet Q-tip is very handy in this situation. Using the Q-tip, gently rub the genital area of the baby mouse after every feeding. This stimulus will cause waste excretion and will eventually teach a recognizable sensation of having to go to the bathroom. Thoroughly dry the infant to prevent urine scald and bacterial infection.

The wildlife rehabilitator will begin to offer regular mouse food when the baby’s eyes open, even though formula will still be needed. A general rule of thumb is that an infant mouse will need to be fed in hourly intervals equal to the number of weeks it is in age. For example, a four-week old mouse will need to be given formula every four hours. After four weeks, a mouse should be able to eat regular mouse food and drink from a water bottle.

Releasing juvenile rats and mice starts with creating a “safe den” while they are in captivity. The rehabilitator will place a small, sturdy box inside the cage, open end down, with an entrance hole in the side. This cave will become the nest den for the mouse, and will be a safe haven when the rodent is stressed. When it is time to release the rat of mouse back into the wild, the animal can be scooped up, box and all, and taken to the relocation spot.

A wildlife rehabilitator will be certain to place the box in a covered area, perhaps an area of thick brush or woodland debris. This will prevent immediate capture of the newly freed rodent by any overhead predators. Food and water should be left out to help the mouse establish itself in the new environment, but should not be placed directly next to the nesting den. In time, the mouse will find a better, safer home and others of its kind.

If you have turned over a mouse to a wildlife rehabilitator, consider what you have just read. A lot of time and dedication goes into the care of wild animals, and it is a nice courtesy to offer some form of support to the rehabilitation cause.

Here are some other advice articles for wildlife rehabilitation:
What to do with a baby bat I found?
What to do with a baby deer I found?
What to do with a baby fox I found?
What to do with a baby opossum I found?
What to do with a baby raccoon I found?
What to do with a baby hawk or eagle I found?
What to do with a baby reptile I found?
What to do with a baby mouse or rat I found?
What to do with a baby songbird I found?
What to do with a baby squirrel I found?

Please be kind to wildlife! Our wild animals are intelligent, and believe it or not, they definitely have emotions!
If you have any questions about this wildlife rehabilitation website, just email me at dseeveld@gmail.com