a change in my hamsters behaviour!!! :(

U1D2C3

he's usually busy burrowing and biting on his cage bars at night, but tonight (and the past 2 nights) he's been extremely quiet. He used to burrow and make his bed in the corner of his cage but i did a cleaning out his cage 3 days ago and now hes made a little bed in his house ( i do this about every 7 to 9 days). He hasnt been as busy the last few nights, and he's a lot more lazy than he used to be!!! i have noticed his food is still going down and he is drinking water. i give him nuts and pellet hamster food and today i have started spraying a hamster vitamin spray on his food. he's not burrowing and when he's in his ball, he moves around for about 10 mins and just stops then and sits there and doesnt move, and my apartment has loads of room for him to roll around in. i dont let him out of the ball unless he's on the couch and im supervising cos he went missing one time for 24 hours, i was traumatized after it (we found him safe and sound)!!! i brought him to the vet mid october to get his teeth cut and he was fine since then.
Also, i have NEVER seen him use his wheel, he might be too big for it, but im worried he isnt getting enough excersise. he's also NEVER chewed on the wood toys i give him, and im really worried for his teeth, but dont know what to do. ! i give him cucumber and apple slices. and also carrot chunks and dog biscuits (which he wont chew on either)!!
he's a good natured little guy, not very affectionate but he has never tried to bite me. but he would struggle if i hold him. also, he's a long haired syrian hamster and he had a big bum with long fluffy hair that waddled when he was walking, but now that hair is shorter and thinner. he doesnt have any bald patches or anything that looks like he's losing hair. its still thick and clean, just a bit shorter. i have him about 4 months now. his eyes are still healthy looking but i noticed a poo yesterday that looked a bit runny (sorry), but he poo-ed in his ball a while ago and it was a healthy one.
maybe im just being extremely paranoid, but i would be devastated if there was anything wrong with him. thanks for reading this big long post and ANY info would be much appreciated!!!

Zapperzy

How old is he? I presume since you've only had him 4 months he's only young? Hair loss and thinning hair is usually associated with old age in hamsters. I would avoid giving him cucumber as it has a high water content and may be the cause of the diarrhoea he had. The occasional slightly runny poo I wouldn't be overly worried about but if he has it severe and more than a few times I would be worried about a condition called wet tail which is potentially life threatening if not caught in time.

What sort of wheel do you have for him? I find the silent spinners brilliant, get the biggest one you can fit in the cage, some wheels are far too small and the constant bending in their backs can cause problems. My hamster only uses hers at night, the only reason I know is that I have walked into the room a few times and she has been in it, up to recently I thought she never used it.

I have no experience with long haired syrians but someone might be able to tell you if these have any seasonal changes in their coats or age related changes not present in short coated syrians?