mouse has growth on buttock

Question
QUESTION: Hi, thank you for having this site where questions can be asked.  We have a female mouse and she recently developed a large tumor/growth on her buttock area.  It takes up the entire area  left of her tail.  Being that it is so large, it has shifted her anus and vagina to the right and her bowel movements have changed.  Her stool is coming out long and skinny and it sometimes takes 10+ minutes for it to pass.  When I swab the opening with vaseline that seems to help stimulate the area and then she passes one to five times.  Her appetite and energy have not changed, but the growh is quite large and is affecting her bowel movement and ability to pass it.  We are wondering how to treat the growth or help her. I think she is between two and three years old.  Thank you.

ANSWER: Hi Diane,

She's a pretty good age for a mouse, you must be doing a great job!  :)  Growths can be one of two things - either a tumor, or an abscess.  An abscess is a pus-filled, swollen infection, and could have resulted if she'd had an injury in the recent past.  This can look very much like a tumor, but actually needs to be lanced by a vet and treated with antibiotics to keep from causing worse infections in the body.  Most mice heal up from abscesses just fine with appropriate treatment.

A tumor, on the other hand, is only treatable *to my knowledge* by surgery by a vet.  How fast is it growing?  If you anticipate that it may become painfully larger in the very near future, you might want to take her by a vet soon and see if they have any advice for you to possibly slow down its growth or ease the symptoms. Whatever the case, a veterinarian is your best option right now, as they can give you much more sure answers and lay out all of your options for you (they will almost certainly have more ideas than me on treatment, as well).  Unfortunately, from here, it's pretty hard for me to say.

In the meantime it sounds like vaseline swabs are working very well.  You can also try feeding foods that will loosen her stools, such as dried fruits, apple slices without seeds, or lettuce, so that things can pass a little easier.  I'm also talking with some other mouse experts about other possibilities, and will get back to you in the near future if I hear back anything useful!

Best of luck, and I hope she feels better soon!
-Tam

Edit - I have been advised by the very wise Natasha to recommend that if you can't get her into a vet in the near future (as in, tomorrow), that it would be a very good idea to start her on a round of tetracycline.  If it's an abscess, it may respond positively to antibiotics.  You should be able to find some in the fish section of your pet store or at a farm supply shop.  Here are some wonderful instructions on how to use it:  http://en.allexperts.com/q/Mice-3824/2010/2/Tetracycline-directions-sneezing-mou

Good luck, and once again, I'll update you if I hear anything else useful!

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

QUESTION: Hi, thank you so much for your response.  I truly admire what you are doing to help others. Over the weekend, I noticed our mouse nibbling on her growth and I think it caused it to open because then clear liquid was draining from it, not blood or puss, just clear liquid.  It continued throughout the evening as in the morning I saw dried liquid spots all over the paper towel that lines her home.  Is this a natural draining which may be a sign of a good thing? Other than this she shows no signs of illness.  She is still very active and eats well.

Answer
Hi again,

Thank you very much.  :)  That's actually a very good sign - the clear liquid actually is puss, and means the bump is likely an abscess.  A vet visit would still be very helpful, since I'm not a licensed professional or anything and I can't see her first hand, but a tumor would not leak!  :)

You need to treat the opened spots she's been chewing on to help with the infection and keep it from getting worse, as well as give her a general antibiotic (the tetracycline instructions).  With the combination of topical antibiotics and oral ones, the bump should go down in size.  Let her chew on it if she needs to, but if she starts to cause serious trauma to the area, consider taking her in for professional advice.  Whatever you do, it has to stay clean - openings can let in new infections.  Here's what you can do - get a bottle of betadine (iodine solution) from your local general store or pharmacy and dilute some down to the color of tea.  Then, soak her bottom in it for a few seconds, or swab the area with it using a cotton swab, gauze, or a very clean finger.  Dry off the area thoroughly, then dab a small amount of triple antibiotic ointment (also available in your pharmacy, if you don't already have some) across any raw spots.  That's it!  You can do that a few times a day to keep her clean.

I still recommend a vet visit one way or another for two reasons - first, they have different types of antibiotics that are otherwise unavailable.  Second, if the leaking is from something more serious that I'm simply unaware of, such as a separate internal infection of some kind, they will be able to let you know.  I certainly hope that's not an issue, but if it was, I would have no way of telling.  However, I'm tentatively very excited for you, because leaking fluid from the bump sounds very much like an abscess, which is treatable (and it sounds like she's doing it herself!).  I hope things continue to improve!  She sounds like a very smart little girl.

Good luck!
-Tam