knot on right front breast

Question
my female cat had a knot come up on her right front breast it is not a solid knot it is soft what do you think this might be? she is on birth control.

Answer
Hi Lisa,

She is on birth control?  What kind?  Sorry, I have never heard of a cat being on birth control.  If she is on estrogen, sometimes that can cause lumps.  However, my best advice to you is to call your vet (the one who put her on the medication) and tell him/her the problem. Let me know if I can help further.  

Hugs,
Barb