Swollen

Question
Hi Tam.

My pet mouse Creamy has a small lump just below her neck.Also I noticed that one of her eye is dark red. I know mice can get red eyes but her red eye is just on the right side. Is that even possible? I've never noticed it before as I've always assumed their both black. At the moment she is still active. She runs, grooms, eat, drinks. Could it just be a fat deposit? I am not entirely sure if that is even possible with mice. The fact that she is not showing any sign that she is sick. What are the possibilities?

Cheers!

Answer
Hi Adrianne,

Having one black eye and one red is called having odd eyes, and usually happens if the fur around one eye is pigmented but white around the other.  It's not very common at all, but it's not a bad thing - it's very cool!  I would only worry about the eye if it becomes swollen, discharges, or looks irritated.  It's likely just a neat little characteristic, unique to your pet!

The lump is a bit of a concern, but it's hard to guess at what it could be without a vet taking a personal look at it.  Growths are usually one of two things - either an abscess or a tumor.  An abscess is an isolated infection that swells up after an injury, like a scratch that got really infected.  Edema, or a fluid buildup, can also occur from an internal injury like a broken bone or torn muscle, but you would probably notice something was wrong with her if this was the case.  Edemas go away on their own as the fluid is absorbed back into the body, but abscesses are full of dangerous bacteria that you don't want absorbed.  A vet can safely treat it, but if you think she may have injured herself and that it could be an infection, it is a good idea to start antibiotics to protect her.  This way, if it is an abscess and it bursts, she is protected from any bacteria that make it into the rest of her body.  If you think an abscess is likely, please either write me back so I can give you antibiotic help, or bring her into your local vet that works with mice to evaluate it.  Abscesses are not middle-of-the-night urgent, but can't be left alone, either.

The second option is a tumor, which isn't as scary as it sounds!  Tumors are just abnormal growths, and they can happen to any mouse, though of course we all wish it didn't.  It doesn't mean your mouse will die of cancer, it just means she's a little lumpy!  The only problem tumors cause is an inconvenience - they don't hurt, but they can make it harder to move around if they become very large.  What I would recommend if you think it may be a tumor is to keep an eye on it - if it doesn't change much, and she doesn't mind it, she can keep on having a pretty normal life.  If it is growing very quickly it might become uncomfortable - this is something you should discuss with a professional veterinarian.  A tumor is not something anyone wishes on a mouse, and they don't go away, but it's also not necessarily a death sentence at all.  As you mentioned - she's still active and happy!

If you can get her into a vet just to check on the lump, that's your best bet.  That way, if it is an abscess you can get it treated right away and safely.  There aren't a ton of other things a bump could be, but you could also look into an allergic reaction if the area appears irritated and swollen, and hot to the touch.  If you can send me back a photo I can give you a better idea - right now without seeing it I could be misinterpreting what a "small lump" is - maybe it's just a bug bite!  Let me know if I can help you narrow it down a bit more, or if you can get her into a vet to be sure.

Best of luck!
-Tam