cobaye in inglese:

They're asking for students to be guinea pigs in their research into the common cold.

We know that a hungry fox will break into hutches and eat pet rabbits and guinea pigs.

Can't you understant this? He used you as a guinea pig.

David would happily be a guinea pig for the pill.

Did you know that guinea pigs, like the ones people keep in cages as pets, actually live in the wild in South America?

I was a guinea pig.

I have three guinea pigs which I keep in a hutch.