guinea pig making weird noises

[floodingophelia]

One of my piggies, Basil, has been making some weird sounds every couple months or so. The first couple times I thought he was just chewing on his pigloo, since it's a low kind of sound. But then today I heard it for the first time in a few months, and I realized it was Basil. I listened carefully, and it sounded as if he was throwing up, except I know that they can't. It's a low sort of gurgling noise that I never hear. And I'm positive he wasn't purring.

I went over to the cage and took a look at him and he seemed fine. He even ate some parsley I fed him, and has been fine all day. I'm just a bit worried that there might be something wrong with him. Any ideas?

 

[PiggyPaws]

I have heard that when guinea pigs hiccup it sounds like they are throwing up...