Sexing newborn pups
So our rescue just had pups, and I’ve made a preliminary attempt at sexing them. I’m pretty sure we have two boars and one sow, but here’s my question: how old do they have to be for the penis to extrude? I obviously want to make 100% sure what their gender is, but they’re only three days old and there isn’t much down there to pop out. Thanks in advance!