GDV surgery for Admiral

Hello, I am creating this GoFundMe on behalf of my sister and her dog, Admiral. Admiral is a 3.5 year old Great Dane who suddenly showed signs of an urgent medical issue lastnight. She rushed him to the emergency vet and they ran some tests. She was informed it was bloat (gastric dilatation and volvulus) GDV. He underwent emergency surgery, his stomach was twisted. Once inside they realized his spleen had been compromised and it had to be removed. He is now having arrhythmia and was taken back to a vet for observation. The arrhythmia is still ongoing and he will be returning to the emergency vet overnight. Until the arrhythmia stops Admiral cannot go home. They are looking at costs from $7000 and up, the hospital stays to observe him are $2000 for a few hours.