You've done well to pick the backlighting, it's making the best of nature.
The problem is that it can make exposure difficult, on a few of these the exposure on the faces has suffered. A tiny pop of fill flash would be easier to manage than a reflector with the dogs, although a bit of shadow lifting in post might get you close.
As above though, the biggest issue is the distracting backgrounds, get them out for a walk somewhere with cleaner backgrounds. As with most photography, the success is in the planning.