Field season in southern Nevada opens while the afternoons are still running past 100 degrees. That timing is why the first weekend of dove season tends to fill local clinic schedules with a predictable list: split paw pads, grass awns wedged into an ear canal, and a dog that was bright and steady at home and flat on its side by nine in the morning. Most of it is preventable with two or three weeks of preparation.
Start with the boring paperwork. Confirm rabies and core vaccines are current, because a dog working public land meets other dogs, standing water, and wildlife. Ask your veterinarian whether the rattlesnake vaccine makes sense for the ground you hunt, keeping in mind that it is not a replacement for avoidance training and that clinics differ on how strongly they recommend it. Check that the microchip registration still carries a phone number you actually answer, and put a plain tag on the collar with that same number, since a dog that breaks off after a covey is not going to find its way back through an app.
Then condition the animal rather than the gear. A dog that walks the neighborhood twice a day has soft pads and very little heat tolerance. Build distance gradually on the surface you will actually hunt, at the hour you will actually be out there. Carry more water than seems reasonable and offer it before the dog looks like it needs any. Learn what early heat stress looks like in your own dog, which usually means a wide flat tongue, thick saliva, and a gait that starts to wander. Put the dog in shade at the first sign, and end the morning if it happens twice.
The handler's preparation reaches the dog too. Noise conditioning goes badly when it is compressed into opening morning, and it goes badly when the person holding the leash is rushed and flinching. A few unhurried range sessions in late summer, starting at distance and closing slowly while the dog eats or plays, does more for a gun-shy young dog than anything on a shelf. Handlers stocking up for that kind of practice can pick up bulk ammunition and accessories at a gun shop just off the 215 on West Russell Road, which is a much shorter errand than the drive out to most of the public ground.
Do the post-hunt exam every single time, in good light, before the dog gets back in the truck. Run both hands over the whole body for cactus spine and burrs, check between every toe, look at both eyes, and lift each ear. Watch for limping, retching, or dark urine across the next two days rather than waiting to see whether it clears on its own. Put your clinic's after-hours number in your phone before you leave the house, and find out now which emergency animal hospital in the valley sits closest to the ground you plan to hunt.