Well I am not sure I have any real advice, here we have a privacy fence about 8' tall, but we only have an acre lol so a little less than you are having to fence in. Back in sweden though, where I had both horses and dogs. I had about 30 acres or so, divided into several different pastures, I never tried to fence in both dogs and horses BUT the fences we had well the dogs never went out when they were with me in there and they never went in to the horses when they were on the outside with me either so I guess it worked on both of them
We had a four rail fence about (hmmmm converting from metrec hehe) between 6' and 7' but since we had both bigger horses that were showjumpers and small shetland ponies for the kids well that fence was okay for the big oned but the little ones are real escape artists, so we added electrical fence inbetween the rails the white electrical fence "bands" the 1" wide, we had them under first rail, between first and second, and between the second and third.
Like I said we didnt try to fence in the dogs there, but it seems to have worked real well, and since we started the electrical bands so low down both the smaller dogs and the big dogs never tried to go through there.
Marit