Surgery is the only option to remove it. There are no medications to rid of it. I have two females with tumors and my vet wants over $500 to remove the tumors for each of them. Check the fees at your vet office, I am sure they are lower than that, since my vet seems to be the only butthole with outrageous prices. I feel your pain. I have had 4 females that had tumors- it sucks so much!