The reason the dog holes are only 2 1/2" deep is that I only have a small table top drill press. Once constructed I will thru drill the holes the rest of the way. I tried to find a way of getting the holes all the way by flipping the boards over but this might lead to misaligned holes. Also, I will be adding holes to the legs on the sides to allow for waste to fall out and to remove the dogs where they are at the leg joint locations.

CHRIS, Charlottetown PEI Canada. Anytime you can repurpose, reuse, or recycle, everyone wins!