Guinea pig not eating and drinking like he shpuld

Question
Hello
My question concerns my male guinea pig Henry, he should be about 4 or 5 years old.
He used to eat a lot, clearing his hay rack at least once a day, and finishing his water bottle every two days. I noticed he's not too keen on his food anymore, and he isn't drinking like he used to. But he is still eating and drinking, just not as much. I was wondering if this had to do with his age? I checked his teeth and they weren't overgrown and he seems healthy.
Thanks for your opinion.

Answer
weather tends to play a bigger role than age but both are a factor. keep a eye on him and so long as he isn't looking thin, and is stilld rinking and eating then don't worry, as soon as you think he's stopped call the vet, the sooner it is treated then the better.

best of luck