Cat mammary glands

Question
Hello and thank you for your service !
Our 15 months old cat has developed swollen mammary glands one week after beeing spayed. It has been 4 weeks since surgery and the glands are still large and tender.
The vet didn't do anything about it, just said to keep an eye on it. But I am very concerned. Any advise ??
Thank you, best regards,
Anika

Answer
This is not normal, and I have not seen this happen before.  Is she showing any signs of heat behavior or running a fever?  Is there any discharge from the glands?

I would probably recommend a course of antibiotics and try to put compresses on her glands.