The dog models are evenly and efficiently constructed using primarily quad polys. With meshsmooth turned off they come in under a thousand faces per model.
BONUS: Extra dog included. The extra dog is not rigged but is very close in body shape and with a little tweaking the rig should be easy to apply.
Dog Poly model with Meshsmooth and Physique modifiers
Second bonus dog
The poly counts listed above are for the entire scene with meshsmooth level 1 applied to both dogs (Polys: 22159, Vertices: 14951).
The individual dogs are each approximately between 2400 and 3400 polys and between 2400 and 3400 vertices at meshsmooth level 1.