We're in the Southwest all the time. We love it. It's not like every 5' you're going to encounter a scorpion or snake. We've never seen one around the campgrounds or even boondocking in the desert. We have seen a couple while hiking but they just scooted out of our way. They're not going to chase you.
Keep your dog on a leash and you won't have any problems.
Did you know that there are scorpions and snakes, including copperheads and water mocasions (which are highly aggressive and not even found in the Southwest) and black widows and brown recluse spiders in Florida, the South, the Midwest? It's not just the Southwest. :)