Understand Your Breed
While almost every dog can hike at least a mile, some breeds make more suitable hiking companions than others.
Dachshunds have chronic back problems, which can be exacerbated by excessive exercise or strenuous hikes, says O'Sullivan. Most can navigate a manicured, mile-long loop, but anything that involves scrambling over boulders or covering long distances isn't a great idea. "If you want a great exercise partner, opt for a lab," she says.
Scrambling, along with cold weather, also applies to toy breeds like Maltese, Yorkshire terrier, and Chihuahua, says Mary Burch, PhD. Burch is an animal behaviorist at the American Kennel Club and she is an expert on breed behavior. "Some breeds can easily overheat, so for summer hiking in a warm climate, breeds such as the Pekingese, bulldog, and pug would be happier waiting for you in your air conditioned hotel room while you sweat it out on the trail."
There are innate breed behaviors to consider too. Hounds, for example, are often completely ruled by their noses. While that doesn't count them out as hiking companions, they're more likely to wander when off-leash.