Guinea Pig has diarrhea

Question
My guinea pig got mild diarrhea after I gave him too much hay. I took the hay out overnight and his poop returned to normal. Otherwise he acted fine, no signs of illness. It seems like every time I give him hay now that his poop gets a little runny. Could the hay be old?

Answer
Hello Lora,

Check the hay for mold. Usually smelling it will give you some idea. If it smells off, there is probably something wrong with it. I would advise switching it even if nothing appears to be wrong with because it shouldn't be making him have diarrhea. Maybe switch to a different type if you have to. I'm assuming the hay you are using is timothy? If you buy a new bag and the same thing happens, try switching to orchard, bermuda, or meadow (to name a few). If he's always been on this hay and never had a problem before, just buying a new bag should solve the problem.

-kkat
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