Dog Lump/Tumor on Hind Foot

by Wendy
(Indiana, USA)

I have a 4 year old, 9 lb, female Jack Russell with a quick growing lump on her right hind foot near the toes. It is oval-shaped and the skin has changed color in the last couple of days.

My local vet (and I) assumed it was an abscess, but when he opened it up this morning, he found that it was not. It is a tissue growth he has not seen before, doesn't involve the bone and has what looks like joint fluid in it.

He is shipping a sample off, but I'm hoping to find someone who has seen this before. Thanks...