When is a good age to introduce my newborn to our family dog?

I had confinement at my mums place, and they knew each other ever since day 1 we discharged . My dog was actually a little too jumpy at first, was afraid he would accidentally jump on my son. So we will hold onto him and let him smell. My dog always call for us when the baby cries. Now my son always go sayang my dog(except he didnt realise it's actually kind of like smacking him), but my dog enjoyed getting smacked by my son anyway. Now, They will race each other too.