Help Rescued 12 year old Yorkie

Hi , this is Tina and Jeff. We have never done this before but need help with a 12 year old Yorkie we just rescued. This little guy has been out on the streets minimum of 1 week and maybe 2. We posted everywhere and no one claimed him and there is no chip. We received him from another rescuer that needed help. We took him to the vet and now understand. He has horrible teeth issues and looking at multiple extractions. The vet bill today was over $600.00 with just IV , antibiotics and other meds. You don’t have to give but hoping you want to . We want this little fellow to die of natural causes in our home being well cared for instead of in the streets. Please don’t judge us we are just trying to help a little doggie that can’t help himself . He is already enjoying himself with our other 3 animals. Thank you for reading and anything you choose to give.