For you, I'm inclined to recommend really breathable boots that use a lot of mesh fabric. For example, if you can find them over your way, the Merrell Mesa Ventilator Mid ($80 U.S.; www.merrell.com) is a comfortable, light boot that uses leather and mesh construction for high breathability. Waterproof? Not on your life. But in hot conditions, ideal. It comes in a low-cut, trail-runner model for $75 if you need a less clunky, lighter shoe. The Vasque Breeze ($110; www.vasque.com) offers similar materials in a slightly heavier boot for bigger loads.
Otherwise, look for an all-leather boot without a waterproof insert: Scarpa's Delta M3 ($219; www.scarpa.net) is a superb example. Its 2.8-millimeter leather uppers meet the criterion of "waterproof," but it's still much more breathable than a boot with a waterproof insert. Too hot in the desert? Well, possibly. Some people are prone to hot feet and some are not. And, it's good for either extended day hikes or big weeklong trips. Lowa's Tanark Mid ($170; www.lowaboots.com) is a similar boot, though a little less rugged than the Scarpa.
Remember, too, that a good pair of light, wicking socks will go some way to helping mitigating foot sweats. Pairs from SmartWool (www.smartwool.com) or Wigwam's line of Ultimax hiking socks (www.wigwam.com) should help keep your dogs drier.