Someone is walking their dogs.
A person tends to their pets.
The walking of dogs implies tending.  Dogs are a common type of pet.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_dog(x2) & of(x2,x1) & n_thing(x1) & n_person(x1))
exists e1 x1 x2.(to(e1,x2) & n_pet(x2) & of(x2,x1) & n_thing(x1) & Actor(e1,x1) & v_tend(e1) & n_person(x1))