Standard Rescue Mutt
Weight: Any size you want.
Best Qualities: The right mutt, trained correctly, can do anything the others on this list can, with less risk of the genetic health problems that often come with purebreds. Also, if you adopt, you're probably saving a life.
Drawbacks: Mutts come in literally every dog shape and size, from tiny and lithe to huge and lumbering, so adopting a mixed-breed puppy can be a bit of a crapshoot. Knowing the dominant breed is critical information if you want an active dog: You want it to have genes from dogs that like to run and be challenged. But that's harder than it looks.
"When people guess at the primary breed of a shelter/rescue dog, they are guessing incorrectly over half of the time," says Sherry Woodard, an animal-behavior specialist who works with the rescue group Best Friends Animal Society (BFAS). Kennels, and more readily available DNA testing, can often help, but one basic rule is to pick a dog with a long snout. The shorter, smushed face typical of bulldogs and boxers can cause breathing problems and hampers panting, which is how dogs cool themselves.
Adopter's Guide: Wherever you are, there's often a shelter nearby. Visit, look at the dogs, talk to the volunteers there. Many kennels will let people foster dogs before committing. If you're adopting an older dog, make sure to see how he or she interacts with other animals to test for aggression, and to determine if he seems controllable off-leash. "Life experiences affect behavior," says Woodard. "If you spend time walking dogs, you can watch how the dogs feel about being near other dogs." Staffers with rescue groups can help you test how a dog does without a lead, and BFAS recently partnered with the dog gear outfitter Ruffwear to create the Ruff Adventure Dog Adoption Program to "connect active dogs with active people." Ruffwear covers adoption fees and dog airfare from the BFAS sanctuary in Utah to new homes.
Most good shelters screen for health problems when dogs arrive, but you'd be smart to take a dog to a vet for a full screening before committing to an adoption. Woodard says that it's impossible to know if a puppy is going to grow up to like running alongside a bike or riding in a kayak, but nearly all dogs can learn to love more basic adventures, like hiking. The key is to start training early, build up slowly, and use positive reinforcement — basically, treats — to reward a puppy during a hike, or for staying when you command it not to chase a squirrel. Also worth noting: You can rescue purebreds, too. Every breed in the AKC registry has an affiliated rescue group, or at least has connections to people who specialize in saving dogs of that breed.