This article is from the WSSF 2014 AFRMA Rat & Mouse Tales news-magazine.

Rat with lump, photo from Shala Thomason.

Shala Thomason, Facebook
Q I have a 12-week-old Dumbo rat who I was able to adopt for free through my job because she had an abscess on her shoulder when she was about 8 weeks old. The vet lanced and drained it and with antibiotics it went away. Two days after her antibiotics were done another appeared under her right front leg. We tried to drain it but it wouldn’t drain and felt more like a tumor. Over the last few weeks it grew and grew and had 2–3 lumps that seemed to form; however, now it almost looks as if two of them have disappeared, there’s a wound where they were that makes it look like they burst open, and the top one is slightly bigger but now it’s soft and squishy. The photo shows how it looks today. The darker part in the middle is hard but the rest is squishy and you can see underneath where the other one opened and drained out. Has anyone dealt with something like this before? We don’t really know what steps to take next with her. Thanks!

Answer by Karen Robbins
A I would definitely have a vet check this out and possibly do a biopsy of the lump to see what it is. If it is a tumor and burst open, then you should see about getting it removed and sent in for pathology to determine the type of tumor.

Update: The entire thing opened up and drained out by itself yesterday! Doesn’t feel like there’s any tumor material in there, it was all abscess. Any idea what can cause a 12 week old to already have had two of them? This second one was after she was separated from other rats so it wasn’t a bite.

Answer by Jeannine Porter
A I had a rat years ago that started with abscesses around her ears at the age of 10 weeks old. It was caused by mycoplasma attacking her ears rather then respiratory. This continued until her death at age 1.5 years. What helped for us was a low dose of Baytril/Doxy twice daily during flare-ups to control infection, regular nail trims, and biweekly baths—the idea was to try to keep her as clean as possible on the outside and fight the internal infection. She lived with her sister rat as a companion who never showed any issues and passed at the age of 3 years.

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