I don't think that the location of your inlet or intake is going to resolve this issue. This is a unique scenario. I think what you are going to require is some sort of a sediment trap or chamber to catch all the dirt and dust (now suspended mud) and hair, etc. that the dog is going to introduce into the pond water before it reaches your main filter unit.
You might wish to look into adding a vortex sediment separating filter or a radial flow sediment filter.
I have been working on a DIY design for such a filter for my river cabin fishing bait pond. I am going to be tossing lots of dirt and mud and rather nasty fish into my bait pond so I need a method to clean the water of this debris before it reaches my mechanical and biological units. I have so far come up with a design that should work well, but I have yet to build it. Check it out in the DIY forum under the title "AXIAL FLOW SOLIDS SEPARATOR". Go to post #16 to view my latest design version, but check out post #9, too.