That's good news. A lot of the time cat food is simply just too "rich" for dogs of any size. It's all meat since cats are carnivores.
The bloody stool could be from the diarrhea itself, so if it is cleared up, that is good.
The vets recommendation on food allows for fiber (to bulk up the stool) and protein but will be gentle on the stomach.
As far as waiting, I personally prefer that you wait until they do have more weight on them before the anesthesia due to the risks.
Congrats on your baby! Glad is better!!
