I'm sorry to hear that at least one of your furkids may be sick. Hopefully you'll be able to find out which one and that it isn't anything serious. I agree that yogurt and pumpkin would be a good thing to try and I don't think it would hurt to give it to all 3 of them. You might want to call your vet and ask some questions before giving them anything just to be safe though. Please keep us updated.