Drying of a dog's fur One day, I started to wonder, why a washing machine needs minutes to dry clothing when a dog can shake off most of the water contained in it's fur in a few seconds.
From my knowledge, the drying process depends in both cases on the centrifugal force and hence on the rotational speed. In this case, the washing machine should clearly win over the dog since it produces a higher rotational speed, but that's obviously not the case (judging from my personal experience).
I think there must be another cause, but what is it?
 A: Dog hair is not an absorbent substance. The dog shakes water off from between the hairs unlike a machine which must shake water out of the fibers. Also, the dog shakes in open air which allows all water to leave. In the machine there are holes to allow water to leave but not an overall open space. Some water would also be trapped between the surface the clothes are resting on. So, it does a few cycles to allow clothes to change position and remove as much water as possible. Dog wins.
A: Well, let's make a comparison with wool, a quality woollen garment.
I think that a woollen garment, right out of the centrifuge, will already feel quite dry to the touch, and will not feel damp when you put it on. I think when you weigh that woollen garment you will find it still has an amount of water absorbed in it that would make other types of textile feel damp to the touch. Wool is just that good. Even with some water absorbed it will still provide adequate insulation.
I think that for a dog a healthy fur has that property too. Very quickly after shaking off water the fur will stop feeling damp. 
I also expect that healthy fur is somewhat water repellent due to fats secreted by the skin. (I expect that sheep's wool has that quality too, but of course that quality gets lost in washing with detergent.)

later edit:
It dawned on me that the above answer is at best incomplete.
It you use a standalone household centrifuge then you will notice that the bulk of the water is driven off in the first ten seconds or so. After that the flow quickly dwindles to a trickle.
Dogs have a body temperature of 39 degrees centigrade, which of course will be helpful in drying the fur quickly. I imagine that when a dog has been in the water and he has shaken of the water his instinct will be to run around, generating heat.
(I'd be interested to hear dog owners about that. If your dog likes to swim, when he has shaken off, is he all exited and running, or will he calmly walk by your side?)
