Literally I felt so bad
after hearing this news, even after owning 7 hamsters I still cant overcome such kind of loss. I personally felt that he would make it but life is not in our hands, as the vet was not exotic maybe he couldn't tell you the root cause or the exact infection. Moss's bottom looked like that bcoz when he peed, he probably didnt clean it and during this stage hamsters are so weak to do that resulting in dirty bottom. I hope you're fine and Fly high little moss, you'll be loved always ❤