The New Adventures of Lassie (2014)

S1E13 Where's Lassie?

While hiking in the woods, Zoe decides to linger with some older girls she looks up to, leaving Lassie to head home alone. When Zoe returns later, she’s alarmed to find that Lassie hasn’t arrived. As the entire community rallies to search for the missing dog, Zoe realizes she’s the only one who truly understands Lassie well enough to track her down.