Not sure about that, but if you ask me, a really small dog only weighs up to 7 pounds - or otherwise said, this motor weight as much as four fat Chihuahuas ( https://en.wikipedia.org/wiki/Chihuahua_(dog_breed) )
Lol. I was confused by it also. I have no idea how much is 28 pounds, and I could imagine how a small dog can be anything from 1 kg to 10 kg. It happens that the motor weight is ~13kg, but I'm still not sure that 13kg dog counts as "small".
But how many footballs a small dog weighs?