How does the dog get wet?

The dog broke through the ice along the creek bed.

Usually the snow above the hidden pools had a sunken, candied appearance that advertised the danger. Once again, however, he had a close call; and once, suspecting danger, he compelled the dog to go on in front. The dog did not want to go. It hung back until the man shoved it forward, and then it went quickly across the white, unbroken surface. Suddenly it broke through, floundered to one side, and got away to firmer footing. It had wet its forefeet and legs, and almost immediately the water that clung to it turned to ice. It made quick efforts to lick the ice off its legs, then dropped down in the snow and began to bite out the ice that had formed between the toes.