[sushi_78]

Hello, If you don't have weights on the scale to compare, it's possible he's just growing and changing shape. Similar to how human toddlers are very chubby and then change shape as they get older.

Now that you have a baseline weight of 89g, I'd suggest weighing him once a week for a while to make sure he's still gaining weight.

You may be able to check his teeth yourself by holding him on his back and parting his lips slightly. He should have two top ones and two bottom ones, and each pair should be the same length and straight. However you might prefer to have this checked by a vet, especially if he isn't very tame yet. You can also watch him eating to get an idea of whether he might have a tooth issue. A hamster with tooth problems may not be able to eat hard foods at all, or they may just take a very long time over them, especially ones they have to shell like sunflower seeds. My gerbil recently broke her tooth and I watched her take 8 minutes to eat a sunflower seed (she's fine now - it grew back perfectly).

As he's very young, 89g could be fine for him. He will continue to grow for some time.

Hamsters do find changes in environment stressful so I wouldn't suggest taking him on any more visits. But it might not be what caused this issue (if indeed there is an issue).

You could take him to a vet for a check for your peace of mind and to be more sure he's ok. Alternatively if looks well you could give it a week and weigh him again.