Breed Isn't Everything
Yes, there are toy poodles that can hike until sunset. And there are labs that hate water. Genetics only account for so much. Still, knowing a bit about the breed or mix can give you insight into what they may or may not go for. At the very least, take a breed's physical characteristics and limitations into consideration. Pugs and other short-nosed dogs shouldn't be pushed aerobically, especially in hot places. Likewise, dachshunds are known for back problems, which makes scrambling over boulders a no-go.