Oh -one thing to be extremely careful about is -Do the Rolaids contain XYLITOL?? (artificial sweetener) If so, this is toxic for dogs, and if you haven't already taken him/her to the vet, do so immediately.
Hi, I am sorry because I wasn't here yesterday when you posted. I hope your dog is okay.
Rolaids contain Calcium Carbonate, which in small doses is pretty harmless, and is poorly absorbed by the dog's system unless paired with Vitamin D.
The only thing to be watchful of is they can cause constipation. And possibly thirst. But fluids will help flush the Calcium out.
A dog with normal kidneys should be able to tolerate a few Rolaids.
But please, if your dog develops any worrying symptoms at all, if there is any vomiting, diarrhea or constipation, do call your vet, or an emergency vet.