Medical Corner:
Tumor Study

Kaleigh Hessel
From the March/April 2000 Rat & Mouse Gazette

I have recently been having a big problem with tumors in my female rats. Of the four rats I currently have that are ages two or more, two have had at least one mammary tumor and one has a pituitary tumor. I have also lost three other older female rats to cancer in the last six months. Searching for a solution besides spaying, I came across a web site where hundreds of research abstracts can be viewed. Let me say that I do not wish to offend anyone in siting animal research. I hate to think of the things that are done to rats or other animals in the name of science. However, every once in a while, something comes out that might actually be helpful for our pet rats.

In a study done in Japan, rats were divided into four groups. One group was fed a diet, 10% of which consisted of Miso, a Japanese fermented soy bean product. The next group was treated with Tamoxifen and fed a 10% Miso diet. The results were impressive. The rats being treated with Tamoxifen in conjunction with the Miso diet had a much lower incidence of tumors than any other group. Only 10% of the Miso/Tamoxifen rats developed mammary tumors. Compare that with 91% in the control group, 77% in the Miso only group, and 68% in the Tamoxifen only group.

There are limitations in applying this information to our pet rats, however. These were induced tumors in young rats. That makes it a little harder to generalize it to our pets who usually get spontaneous tumors in older age. Still, could there be any harm in adding Miso and other soy products to our pets diet? And, early treatment with Tamoxifen, along with the Miso diet could slow or reduce an existing tumor. I have added Miso to the molasses mix I feed my rats. We'll see if it makes a difference for my younger rats.