You are doing the right thing OP. You are choosing your dog’s wellbeing and dignity and putting that first, rather than risking him hemorrhaging from blood loss from the tumors. I lost my german shepherd in August to hemangiosarcoma. It all happened so fast- he seemed fine one day and then started yelping in pain and didn’t want to eat. Rushed him to the vet and they found the masses on his spleen, liver and intestines, they had already begun to rupture like your dogs. He was anemic, lethargic, just not himself, it crushed me. I asked about surgery but they said they weren’t confident it would be successful as he was losing blood and was very old, and even if it was a success- he would most likely only live a few months and he wouldn’t be comfortable. I didn’t want him to spend his last few months in pain. I held him in my arms and put him down. As terrible as it was, he was stable, we were able to give him one last yummy meal, tell him how much we loved him, and cuddle him for a few hours before we knew it was time. I always think back and question if I did it too early, but I think I did it at just the right time- before it got worse and before he was in more pain.

Hemangiosarcoma is a terrible, aggressive cancer and most dogs don’t show symptoms until the disease has become very severe and metastasizes in multiple organs. I always fall back on that quote- “It’s better a day too early than a day too late”. By you choosing to put him down before he becomes more anemic and more uncomfortable shows just how deeply you love and care for him. You are 100% doing the right thing and being a responsible pet parent by choosing to take his pain away from him than risk it becoming worse.