Ask a Cat Question, Get an Answer ASAP!
Hi. My name is***** Thank you for your question. Can you post a picture of what you're seeing?
Good job on the picture. That area looks very suspect for an abscess that has started to drain. The good news is that there isn't a big worry for something like sepsis / septic shock from this. Typically they are persistent problems at that location until they are treated. She is eating well and being affectionate, so while it is definitely a problem that needs addressed, it shouldn't progress until you get her seen. That local area most likely will get a little more worse looking with the discharge but that is most likely it. At the vet's office, they will clip that area and then most likely flush the pocket and then start her on antibiotics. Try to get her into your vet as soon as possible.
The most likely cause is another cat biting her in that area. If she has access to outdoors, then she most likely got into a skirmish with another cat.
If her and her sister play rough, then I would be curious that was the cause of it. This should heal with the treatment your vet gets going and it shouldn't be recurrent (unless the rough play gets this rough again).