You don't real 'get' the dog, you just can take it on walkes. Heres how:
First, go to the petting zoo and read the sign thats next to the opening to the dog's pen.
Wright down what days it says the dog is out, so you don't forget.
Second: go to the petting zoo every day and get lots of feed from tober (perferibly
meat).
Third: every day the dog is out, go and feed it... I think you can feed it twice every
time switch.
If you keep doing this, you will be able to take the dog on walks.