I don't see cow hocked. I think his back legs look very nice actually from the behind angle. He is sickle hocked. But that could be an advantage depending on the discipline that you decide to put him in.
Overall, I think he's a nicely built little guy. That may be subject to change though as he grows. Of course, you already know that.
He's a tad butt high, but...He does seem to be growing pretty evenly. He has a nice shoulder, nice neck, pretty face. And he has a nice hind-end too. Croup is looking a tad steep.
"The greatest pleasure of a dog is that you may make a fool of yourself with
him and not only will he not scold you, but he will make a fool of himself too."