My hamster is over a year old, and he's bald. Not completely, but nearly! He started going bald months ago, so it can't be his age. We took him to the vet who gave him shampoo but he didn't like it and it never worked. He's lively, eating and drinking, but why is he bald?
Last year my hamster started goin bald on his belly+across his shoulders. We took him to the vets who gave him injections for a skin infection. Sadly he died from old age a few months later :-(
Who knows lol! Could just be one of those things, like when humans go bald .... maybe you might want to try a comb-over style if he is long haired? A hamster Bobby Robson ;0)