Get a long balloon
Inflate the balloon, leaving a few inches uninflated at the end
Tie the end securely
Twist the first section to make the nose
Twist the next section to make the ears
Twist the next section to make the neck
Twist the next section to make the front legs
Twist the next section to make the body
Twist the next section to make the back legs
Leave the remaining balloon as the tail
Adjust the twists so the dog shape holds together