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Mice/Constipated mouse


QUESTION: I have been hand-raising a baby mouse from the age of about a week old. I'm using kitten milk replacer as recommended from various mouse/rat sites.  The problem is the poor baby's belly has become a balloon! She was going a small amount of liquid feces when I stimulated her ano-genital region with a warm wet Q-tip before/after feedings.  It was never a lot and I didn't think that was problematic until now.  Her belly is severely bloated, I can see gas bubbles and liquid feces in her gut and she's stopped producing anything but urine at all.  I tried to combine a small amount of milk of magnesium with the KMR in her last feeding but am not sure how much she ingested.  She's the last of 5 babies to survive and has been thriving despite my mistakes--although I have 10+ yrs exp. with rats/hamsters/mice I've never hand-raised a baby.  Please advise!  Would olive oil in milk work?  Or should I continue milk of mag.? She is not yet eating solids.  Her eyes have been open for 2 days now and she is fully furred out.  Thanks so much!  Sarah

ANSWER: Hi Sarah,

I would consider this an emergency and take her by a vet or wildlife rehabilitator who has experience with orphaned rodents. It could be gas, but it could be a couple of other things causing the distension, and it's not a good idea to wait.

The first thing to try (in conjunction with a vet, not instead of) is to lay her flat on the bottom of the enclosure with the heat pad turned on to its lowest "warm" setting, and stroke extremely gently on either side of the mouse by placing your forefinger and thumb up by the shoulders and petting downwards toward the hips. It should be a light petting, no pressure. This massage can help move bubbles along. However, pups are fragile and this one is already stressed, so do NOT apply pressure.

The second thing, and something your vet can help with, is to add lactated ringers solution to the KMR. If you can't get it from a vet try unflavored pedialyte, but LRS is better. This will help with dehydration that results from loose stools, but won't help move any blockage or gas.

I cannot recommend using milk of magnesia or olive oil because I simply don't know about its safety for mice. Normally I would look that up and get back to you, but in this situation, the most important thing for the pup is to get to a vet, and I don't want to waste any time. I can tell you that both LRS and pedialyte are safe to mix with the KMR, so I'd do that for the next feed if you have one in between now and when you can get to a vet, but again, please try to get in ASAP.

Good luck and please keep me updated if you can.


---------- FOLLOW-UP ----------

QUESTION: The poor baby passed over the Rainbow bridge this morning around 5am.  The last feeding I gave her was KMR+water+a few drops milk of mag. She had a very large stool, probably as a result of the olive oil after this feeding. This morning I found her in final stages of dying, gasping through her mouth every other second.  I left her alone because I believe it would have stressed her more to pick her up. Her belly was still very bloated and gassy and full.  I really believe she was too far along in the constipation/blockage and it was most likely my fault for not cutting the KMR with water. I didn't learn about that until this problem occurred.  I feel terrible that my ignorance killed her, but I did keep her alive for 9 days.  I rescued a nest of 5 pups that has been found in a box of grass seed bags at a hardware store, they were going to be thrown into trash.  3 babies died that night, 4th survived 3 days and this 5th one lived 9 days.  So at least she had somewhat of a life, but she wasn't with the mother long enough to get a good head start.  If there is a next time, I will do better.  I buried her with her sister in my pet cemetery in my flower garden. Thank you for your response, Sarah


Raising orphaned pups is hard even for people who have been doing it for years.  Even when you do everything right, they still have a really high mortality rate.  Don't think it's your fault - it could have easily been something physiologically wrong in the gut, too.  There is just no telling, and there is no blame, either.

I'm so sorry for your loss, but I'm glad she had you while she was here.

Best wishes,


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I can answer questions regarding mice as pets, mouse behavior, color and coat genetics, breeding techniques, and general health questions. I can help with caging and setup, nutrition, social issues, and what to do in most mouse emergencies (such as unplanned litters, injuries, fighting, etc.). I can also assist with questions pertaining to orphaned mouse pups, weaning litters, and questions of mating and birthing. I cannot answer questions about exotic or wild varieties of mice such as spiny or pygmy mice. *****FOR EMERGENCIES, anything requiring immediate medical intervention, PLEASE take your mouse to a professional veterinarian or wildlife rehabilitator who works with mice as soon as possible! IMPORTANT RESOURCES: Raising Orphaned Mice: Orphaned Mice Videos: Natasha's Your First Mouse: General Mouse Help: Mouse Info and Exotic Breeds:


I have enjoyed the companionship of mice nonstop since 2004, and spent a year caring for them in a lab where I learned a great deal about their breeding, social needs, and health. I spent a few years breeding them, specifically working with albinos, marked mice, angora mice, and satins. My education never stopped - I am learning something new every day from current and well-established research thanks to the wonderful folks at the Jackson Laboratory, as well as from my wonderful mousey friends online. I also love learning from my terrific questioners here on AllExperts - you folks keep my passion for these amazing animals alive and well!

East Coast Mouse Association - expired, American Fancy Rat and Mouse Association - expired

Partial University for a B.S. in Microbiology, Partial University for a 2-year degree in Veterinary Technology (RVT cert), C.E. classes in pathogens, aseptic technique, genetics, and applications

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