Yikes. We use a rehabbers guide called "Wild Mammal Babies: The First 48 hours and Beyond" for our dosing guide, and they use 20mg/kg.
I would strongly suggest that you transition him to a different formula. We have had lots of issues with the Pet Lac. It is designed to be a cheaper formula than the same company's Esbilac Puppy Formula. He is old enough to transition to Fox Valley 20/50, which you will have to order.
https://henryspets.com/fox-valley-da...aby-squirrels/
While you are there, order some blocks - he will be needing them very soon:
https://www.henryspets.com/diets/ the first three products on the page/
I would recalculate the amoxicillin stat.