Advice on huge seroma

Question

Shelby's seroma   QUESTION: Hi Sandra,

My female ratty Shelby had a mammary tumor removal surgery 3.5 weeks ago. She developed a seroma a few days later, at the site (upper chest). It drained a lot of clear fluid out of it, a couple days after it initially developed; but then it filled up again, even larger than before. Took her to the vet's a few days after that. He took a slide of the fluid, and said he saw a lot of lymphocytes, which he thought indicated infection. He put her on SMZ TMP. She was on that for about a week, but I took her back to the vet when that didn't appear to be working at all (in fact it still grew a little further while she was on it). This time, he decided to drain the seroma, since it was massive. He drained out 215g of fluid! This was this past Saturday, by the way. Sent me home with Baytril and a diuretic to try to prevent fluid from building up again. Needless to say, though, by day 3 since the draining the area filled back up again completely. Seroma is huge once again.

Sorry for the long explanation. I guess my question is, is there anything I can do to help this thing? I know that the general advice with seromas is to "let the body reabsorb it", but with the abnormal size of this one, I highly doubt that's going to happen. Should I just keep bringing it back to the vet to get it drained, and hopefully at some point it will stop filling back up? Or should I wait until the course of Baytril is over? Any other advice?

I have a great vet, that is very knowledgeable about rats, and he said this is a particularly "bizarre" case. So I'm just looking anywhere for any possible outside experience that may be able to provide me with some other advice.

Thanks a lot.

ANSWER: yikes!  I was just going to ask about the vet and his credentials but if your sure of his knowledge etc...I have to go by your trust in him.  I know of course this cannot be blamed on the vet anyhow since seromas are common right after surgery.
As you may know, a seroma is an accumulation of serous fluid, which is simply blood without most of the cells. If you added the blood cells back in, it would be a hematoma, which is blood that collects under the skin.
The cause of a seroma is usually due to inflammation which can occur for many reasons, such as if the rat chews or pulls at the stitches or if the stitches are causing an allergic reaction, which I was going to ask about next.

I do have to ask if your rat was placed on antibiotics after surgery and if you know what kind of material the sutures are made from. It is also not uncommon for the seroma to contain bacteria if the area is infected, and may have a foul odor to the drainage as well.  I always suggest any surgery done on rats should be followed with antibiotics, particularly the type of broad spectrum that can penetrate pus well in order to prevent and if needed, combat infection.

If the area where the surgery was performed was highly vascular, this is also why the seroma may have developed A normal seroma is a pocket of clear serous fluid that can easily form in your rat immediately after any type of surgery.  If the small blood vessels are ruptured, sometimes blood plasma may start to seep out and it becomes inflamed by the dying cells. These cells may also be found in the fluid as well.

My suggestion is to have the vet place a temporary drain in the seroma rather than having to keep bringing her back in. This can be done very easily and the rat usually leaves it alone. Has the vet removed the stitches from the surgery?

---------- FOLLOW-UP ----------

QUESTION: Thanks for your quick response.

I don't know what the sutures were made of. There weren't any external stitches or staples. He just used some kind of internal stitches (I think the dissolvable kind-- could she be allergic to those?), and surgical glue to close the site. She did pick at the site a little bit on the first day, but nothing that appeared too bothersome.

She wasn't on antibiotics at first, no. I think he just gives them a shot of Baytril after the surgery, and that's it. Normally my rats have fared well with that method. She got put on the SMZ later on, when we took her back. She's on a 20-day course of Baytril now, though.

When it initially drained, though, it didn't seem infected to me (it started draining when she was on my lap so I witnessed what the fluid looked like). It was clear and didn't have any odor. The fluid he drained this past Saturday, however, was yellow.

I will call him and ask about the drain this weekend. Hopefully that will cure this issue.

Can a rat die from this?

Thanks.

Answer
The sutures can be the cause of this yes if she is allergic to them.  all rats are different, so what may work ok for one may not work ok for another.

As for dying, to be honest, rats can die from anything really, esp if stress gets to be a problem because this lowers the immune system and this is when they get sick.  Infection is the big factor here but she is on good antibiotics so hopefully she doesnt get worse to avoid sepsis.
To be honest, I would be surprised if this would end up being fatal but again, I have seen alot of things when it comes to rats.  Lets hope she continues to heal. PLEASE keep me posted!!