[Lilafernim]

Again, I am no expert, but if you did a full clean out maybe that’s caused him stress and it’s a result of that, or I remember you said where you are it was hard to get paper substrate so perhaps the brand you have might be dusty or cause allergy. As Ria said, that’s what I meant when I said it didn’t look awful as it doesn’t look inflamed or like he’s been scratching at it which doesn’t make me think it’s something bad or infected. Probably an environment thing but I really am not sure.

Thank you Ria for replying as well as I'm not sure the best diet mix of a dwarf hamster! I’ve just heard diet can influence fur loss before. As Ria said also you could put the water bowl on a flat surface or if you have a pet shop of any sort near you, you could get a drinking bottle and then paper can’t get in either. If he’s only ever used a bowl though make sure just to use your finger to dab the bottle and show him it’s wet so he understands that’s where he can get water from.