Bumps on vulva

I found 2 uneven bumps on my dogs vulva 4 days ago. Checking again today, one of the bumps looked to be crusted, and now that bump is slightly filled with puss. The other bump remained the same (larger) size. We haven't noticed her licking the area more than normal, or showing any difference in behavior, but I'm worried she may be in pain and would like any advice is it exists! Thank you!! -- Dog is an 11 year old female Weimaraner (named Piper)

Here's a photo of the area --  I forgot to mention she has Addison's Disease (if that matters in the diagnosis).  

Hello!  Vulval tumours - benign and malignant - are not uncommon, but they are not the only possibility; infectious disease, chew damage and hormonal changes are also possible.  Infection may also be involved.   We would recommend showing this to your vet to be checked.