Do chiggers bite dogs, and if so, how do you combat that on the trail?
Been there, done that. Yep, chiggers (a nearly-microscopic relative of the tic and the spider) have ruined a week or two of my life, and they'll latch on to your dog (or cat) just as aggressively. On dogs they typically prefer the head, legs, and abdomen, and doggie may or may not scratch at the aggravation. Where these pinpoint-sized mites are feeding on tissue, liquefied by their saliva, skin turns reddish--that, and the scratching, may be all you have to make the call of chigger bites.
If you do nothing, the chiggers will feed until satiated, then fall off after a couple of days. If your puppy appears miserable, treatment is relatively simple: A couple of pyrethrin-based dips--available online or from your local veterinarian -- spaced two weeks apart. But that will have to wait until you're off the trail. Another recommendation is a topical anti-parasitic drug, Tresaderm. Your vet will be the best source of more specific info.
It's also important to know that chiggers tend to infest the same locations year after year. The pests are hatched in the spring, and are all gone by October. They thrive during the warmest months of the summer and primarily inhabit warm, low-lying areas with dense weeds and undergrowth. Avoiding trails that you know are a habitat for chiggers during chigger season is sound reasoning. If you want to take a proactive approach: Mosquito repellent works too.
FYI: Rarely will your pet pass chiggers on to you. If you both get them, you probably both tramped through the same chigger-ridden environment.