Little Red Wagon

A fire-fighter was working on the engine outside the Station, when he noticed a little girl nearby in a little red wagon with little ladders hung off the sides and a garden hose tightly coiled in the middle.
The girl was wearing a fire-fighter’s helmet.
The wagon was being pulled by her dog and her cat.
The fire-fighter walked over to take a closer look. 
'That sure is a nice fire truck,' the fire-fighter said with admiration.
'Thanks,' the girl replied. The fire-fighter looked a little closer. The girl had tied the wagon to her dog's collar and to the cat's testicles.
'Little partner,' the fire-fighter said, 'I don't want to tell you how to run your rig, but if you were to tie that rope around the cat's collar, I think you could go faster. '
The little girl replied thoughtfully, 'You're probably right, but then I wouldn't have a siren.'