My Son-in-Law is a Vet Tech and a dog was rushed to his hospital that had been hit by a car. He and the vet did their best to save him but he was too seriously injured.
Son-in-Law held the dog's head in his hands and the dog gave one last look up into his eyes as if to say "Thank you, friend; I knew you did your best" before dying. After that, he had to step outside the hospital to contain himself.
Your story made me cry.