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Pet Rats/Rat with swelling on face


QUESTION: My poor boy has had a swelling on his face that has yet to subside despite seeing a vet and having steroids injected to the site to ease the swelling. According to the vet, the swelling lies below a facial optic nerve thus nothing was removed.

Would anybody have any experience if this could be a tumour of any sort? They did not see any teeth problems, I also do not smell any signs of an infection. He is currently 11 months old.

Here are some pictures of the swelling:

Before Surgery:

4 days post surgery:

It has yet to go down, his review is due tomorrow.

Thanks in advance.

ANSWER: Hi Jasmine,
Unfortunately, this could be cancer. Most of the time, swellings on the face in rats are caused by cancer. Occasionally, it can be a simple abscess. The best thing to do is to just wait several weeks to see what the swelling does on its own. If it is cancer, no treatment will help anyway, and surgery often makes it worse. If it is just a simple abscess, it will clear up on its own.

How long has he had the swelling?

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


Thank you for your response.

I'm still hoping to wait it out, my vet has had some pictures posted here, we first noticed the lump on the 15th of February, but looking at past photos, there seemed to be a small bump since the 9th.

As the vet has mentioned, there is no pus at all, except a swelling down, they said they have checked all his teeth and found nothing.

How long more do I have with my boy if he has cancer?

It depends on the type of cancer. When I've had rats with cancer on their face, sometimes they've had a couple good months still, and sometimes it is only 2-4 weeks. With my rats I've known when it is time to euthanize them because all of a sudden one day they just don't feel good.  But I've had some abscesses take up to a month to open on their own, so you'll just have to wait and see what happens. I'm sorry I don't have better news for you.

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Debbie Ducommun


I can answer any questions about pet rats, but you will probably be able find answers to simple questions more quickly on my website at If you have a life-threatening emergency you can try calling me at 530-899-0605. I am not usually on the computer on the weekend.


I have been "The Rat Lady" since 1985 and am recognized as one of the world's experts on pet rats. I have 3 published books and already answer lots of questions about rats daily.

President of Rat Assistance & Teaching Society

I am a monthly columnist for Pet Business magazine, and my writing has appeared in other magazines. I have 3 published books.

BA in Animal Behavior

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