Wednesday I noticed a large (egg sized) lump on one of my female rats sides, although it moves very easily to her lower abdomen area and back again. Went to the vet today, was an awkward and weirdly quick appointment (awkward mostly because I had to stay in the car because of the pandemic. She said its probably a mammary tumor or an abscess and will keep growing and will eventually impede rat movement, and the treatment is surgical removal. Now something just seems weird. This is a pretty well recommended clinic, but sometimes it seemed like the vet I got was not that knowledgeable. It also seemed weird that they did not, nor did they offer to do a biopsy, they said the only way to know what it is is to send it for an expensive histopathy, AFTER SURGERY. The other weird thing is that it seems very strange for my rat to get a mammary tumor at 8 months old, but the vet did not comment on this. Surgery is not cheap, about $400-450 and they'll also spay her for $150 which seems like a decent enough idea I guess. (They charge a whopping $350 per rat for spaying otherwise). It won't exactly be easy to pay for surgery, but I can do it without any significant problems. But it just bothers me to no end that I don't really know what it is. My rat is young and otherwise healthy, so if its just this surgery and it will give her the rest of her 1.5 years of happy life, I'll do it, but it just bothers me that it could just grow back worse or be something that could be treated with other means, and no one knows because no one knows what it is. Another vet with more rat experience at the same clinic is calling me on Monday, but at this point I just don't know how I should approach this at all.