With the exception of lunch meat, I don’t recommend anyone eating uncooked processed meats like hot dogs and sausage because of the potential of bacterial contamination through manufacturing and/or changes in storage temperatures during shipping and at the supermarket.
Although many of these products state that they are fully cooked, it is always wise to heat them prior to eating. Secondly, hot dogs are not appropriate for children until they have sufficient back teeth to fully chew a food. They’re considered “choke foods” for kids younger than 2 years of age.
As for the hot dogs upsetting your granddaughter’s digestive tract, if she has been eating them and had no reaction, they’re not bothering her. Maybe you can compromise with your daughter. You won’t give her a hard time about feeding them to her toddler if she cooks and mashes them first.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.