rat tumors

Question
Is it possible to buy a rat from a breeder that has modified the gene that causes them to basically always get a tumor(s)?
I would be willing to spend whatever amount of money to get a rat that is not going to get a tumor, but I'm not sure if that's even possible.
Thanks,
Brittany

Answer
Hi Brittany

Its not possible for the tumors to be genetically bred from the rats esp females and the reason is because most of the tumors our rats get are fueled simply by hormones.  Estrogen, to be exact.  High estrogen levels usually are seen in female rats the most and it occurs once menses cease and the rat no longer goes into heat.  When this occurs, estrogen levels rise causing the growth of mammary tumors. Once the female rat develops one tumor, there is a good chance more will follow.
Males can get them too but the good news is once they have it removed they dont seem to produce more, like females do.


The good news is, since we know basically WHY females develop these tumors, we have figured out ways to try to prevent them to the best of our ability, and that means to spay the female rat at a young age, around 3 to 5 months of age to be exact.  This doesnt carve in stone that the female will be tumor free, but it does mean that there is one good chance, around a 70% chance actually, that she will not see a mammary tumor pop up during her life!