Swelling near anus and a tumor question

Question
Hello! I have seven rats in a Ferret Nation cage, and four in a Super Pet cage, all are females. Some of the girls in the Ferret Nation are starting to exhibit some swelling in the vaginal/anal area. The girls in the Super Pet are not. My oldest girl, who is a little over 2 years, has the worst swelling of the group, and it appears as though her vagina is swollen shut. The vet is unable to see her for a few days, but I told him about her condition, and I've been monitoring it for the past few days. The swelling hasn't gotten any worse or any better. I cleaned the cage, and completely scrubbed it down to see if it was something environmental that was causing it, but it had no effect. I also checked on the Goosemoose forum to see if any other rat owners had encountered anything like this, but no one seemed to know what would be causing this. In the past few weeks, the only thing that has changed in the cage is that I bought them new food bowls, and a giant hamster ball that I put fleece in for them to sleep in. I use the same detergent to wash their fleece liners, and the same dish soap to wash their food bowls, water bottles, litter boxes, etc. I'm really worried about them, because no one has ever heard of this happening! Their behavior hasn't changed, all their quirks have stayed the same. Is there anything I can do to reduce the swelling?

My oldest girl also has a tumor to the right of her tail. She has had three mammary tumors before, all of which I chose to have removed. I'm concerned due to the location of this one, it's pretty much behind her leg. Is this operable? If it is, given her age and history, should I get it removed? She was my first rat, so I would like to keep her for as long as possible, but I want to do what's best for her.

Answer
Hi Danielle

It sounds like the tumor is in an area that can be removed, but this would be her fourth surgery, right?  Normally as long as the rat is healthy, age is not usually a factor in surgery but the truth is, how many more times do you want to have her operated on?  Its such a hard thing to have to decide, and with the fact you have 11 females, if they are all intact, you may be facing this with many of the other females down the road as well.  

As for the swelling, if the girls are all about the same age, it could be hormones or it could be a coincidence totally.  I am curious to see what your vet says so please be sure to let me know how it goes.