My oldest boy Maxx who is 7 yrs old is allergic to EVERYTHING and when his tummy hurts (which has been alot in the last 7 yrs) it he shakes - not constantly but he'll shake for a little bit and then stop and then it starts all over again. None of my others do this - with Maxx, I learned alot about veterinary medicine LOL. You can give your baby some pepto Bismol - Max is 7 lbs and I give him a full teaspoon of it in an eye dropper. It does help. Try this ok? Is he eating grass when he goes outside? That's another sign that their tummy hurts.
If it doesn't stop, you need to take him to the vet. Good luck |