Shadows Echocardiogram

Shadow is an 11 year old cat and is in need of an echocardiogram and hopefully surgery to get rid of her infected tooth. She has a heart murmur. We got her results from an xray and sent it out to a specialist and a message board. The people on the message board and the specialist said to not put her under anesthesia or she will likely die. The doctor said that all we can do from here is the echocardiogram. The doctor also said that she has a swollen kidney, even though the enzymes in her kidney look good they are concerned that it could be cancer. The echocardiogram is about 388 dollars and the surgery amount is unknown. Hopefully 500 dollars is enough to get her the echocardiogram, surgery, and anything else she may need including medicine. I will be very grateful for anyones help she is the love of my life. I'm only 14 so there isn't that much I can do and this is our last hope.