You don't say what species they are. If they are adult cornsnakes, they can easily go a month without food. The issue will be water. If they run out or poop in the water, they can die from dehydration. Is there a vet or petsitter that you can pay to check on them? Check with a reptile store...
I supposed to protect a life, I would do what I had to. However, with the experience I have now, I might attempt to get the dog away from the child. Unfortunately, even if you offered to rehab the dog, most cities or counties would not allow you to and would require the dog be euthanized...