Swollen vulva
I have a 13 year old spayed maltese, who was spayed at before a year old (i don’t remember exactly). I noticed that her vulva is swollen and I’m not sure how long it has been like this/if it’s supposed to look like this? It’s been a few months of taking her to the vet numerous times and she tried oral antibiotics, topical antibiotic cream, and antifungal wipes but nothing has changed about it. She was tested negative for UTI. It doesn’t seem to bother her and her urinary habits have not changed. It is soft and has not changed in size at all over the past few months. The vet suggested a dermatologist, but she is a very reactive/spicy dog with a heart condition and I would like to not stress her out if it’s not necessarily harmful/bothering her. Does anyone have suggestions what this could be or if a dermatologist is absolutely needed?
Picture I posted from another sub: