This is a good start but there isn't enough color. The dog needs improvement. It's a bit too basic. See if you can expand on detail of the dog, not too much just a bit.
No you rad it correctly. As is true most of the design process, as new designs come in new ideas are introduced that trigger creativity. The logo tournament description is a good starting point and should be used as reference only. Conceptually we like where you are going but it needs refinement. Our description also says fun, happiness, exercise. When I look at the dog in your design compared to the others it isn't conveying that thought as strongly.
Really appreciate your hard work, maybe a crayola line art but with a more realistic dog would hit the mark?