YSK that letting your dog sniff on walks is very enriching, interesting, and stimulating for them. Your dog sniffing every little thing in the neighborhood is equivalent to us reading the newspaper; its how they absorb information, and will give you a calmer dog!
from /r/YouShouldKnow
YSK认为，在散步时让你的狗闻一闻，对它们来说是非常充实、有趣和刺激的。你的狗嗅着附近的每一件小东西，就相当于我们在看报纸，这是他们吸收信息的方式，而且会让你的狗更平静!