Pet rat with a bleeding tumor

Question
Hi. My rat nellie has had a mammary tumor for a few months now. It opened for the first time in July and at first scabbed over. Now though, so much of the tumor is viable (a circle of about 1.5 cm diameter) that it remains open all the time. I has started bleeding quite regularly. I usually clean her up and then she sorts herself out. Her behaviour is not different - she is eating and playing as normal. She is a bit less active than she was but that is only because she is 2 and a half years old now. Do you have any advice? She doesn't seem to be in pain as when I clean the area she doesn't flinch. The tumor is about the size of a large grape. Thanks :)

Answer
Hi Lu,
Sorry for the delay in my reply. Can you send me a picture? Is the tumor near her vulva? If so, then it is likely to be a malignant mammary tumor, which can be successfully treated with tamoxifen. See the article about this topic on my website at www.ratfanclub.org
Deb