Shirley,
No, I haven't had the misfortune of having either of my kidlets go missing, however, I'm familiar with communicators who do this sort of "lost" work. If it were me, I'd most likely keep looking anyway, just in case, but I'd be keeping in mind what they read so as not to have possibly false hopes. And if your dog was never found, the communications might help to provide some comfort in knowing there was no suffering. If you feel the need to keep searching, here's an excellent site for how to search most effectively; a section for lost dogs, and another for lost cats:
Missing Pets PartnershipI know lost animals are one of the hardest griefs to go through, just like any missing person, as there's little opportunity for any sort of 'closure' if there's no body found. It makes any sort of acceptance harder to reach. And that's why I'd keep looking, were it me. I think going the distance with all the many known techniques would help alleviate the lingering doubt, and at least you'd feel more peace from knowing you'd done absolutely everything you could have to find your dog. You also might find your dog's body this way, so you could be sure. Since I know of cats, at least, who have been recovered after even 2 years of going missing, for me, I'd need that self-assurance that I hadn't given up too soon.
I also know that many communicators won't do this type of work, because it's hard on their emotions, too, AND some say that when they connect, they can't tell if an animal's out of their body or not, depending on what they get from the animal. So I'd also want to be sure and use someone who's very familiar with this niche of communication before I'd be able to take the reading at face value.
I hope the Missing Pets site can help you.
And whatever you decide to do or not do, you can still come here to share your grief.