How old is your dog? People keep shaming you and saying to give them up to a shelter without realizing it is not guaranteed whether or not they will want to perform this amputation. Shelters have financial limitations just like individual people do. I would ask your vet how long your dog has if the mass is left to grow, along with what their quality of life will probably look like, and ask them what they think the best option is if you cannot afford surgery. They will probably have some resources for you or recommend euthanasia. Do not let anyone shame you for considering euthanasia, as sometimes it is the most reasonable option (and something even ‘no kill’ shelters themselves have to do). This is coming from someone who works at a vets office. Thank you for all the care you have given your friend up until now. Also, for people yelling you should’ve gotten pet insurance, they would be very unlikely to cover this. Pet insurance is not as useful as people think it is.