a guinea pig
can suffer from a heart attack
If it is very overweight
If it is given , too much high starch food in its food ,
and not enough green stuff and sweet meadow hay
it can suffer a heart attack if it is stressed;
by being chased by cats or dogs
frightened by rats or mice .
by being picked up roughly
its hutch in a noisy busy area .
It is the responsibility ,of the owner of a guinea pig
to understand their needs , and keep them safe and well.
here are some good sites ,with some more information for you
Guinea Pig Care
Free pet care information from The Blue Cross - Britain's pet charity
Keep Guinea Pigs as Pets
Everything You Really Need To Know About Pet Guinea Pigs In One Place!