Originally Posted by TalkALittle
The bigger reason for not clipping/shaving down double coated dogs is that you run the risk of the outer coat (what provides protection to the undercoat) not growing back in correctly.
Also, while the slower growing outer coat grows back in, the quicker growing,but more easily damaged,inner coat ends up taking a beating.
The best thing to do for an Aussie or english shepherd (besides breeding for a good working coat that's not too thin OR thick) is regular brushing to remove the undercoat. Part the fur and use an undercoat rake. You can use a Furminator but don't go crazy with it. Do this regularly so that when it comes time for those twice a year super sheds, your dog doesn't have a buildup of dead undercoat. You can also use thinning shears to take bulk out of the coat without completely removing the top coat. A good blow out with a force dryer (or even a shop vac with the hose reversed) can remove any remaining loose fur.
Do not shave your double coated dogs. Maintain them. Their coat helps them to do their job in all kinds of weather. Unless you have a breed bred for one climate extreme and you live in the opposite extreme you should be okay.
If you are a smart farmer/rancher/homesteads you have routines that you do daily, weekly, monthly, and seasonally that keep your equipment in proper order. It should be the same for your dog's coat. If you find yourself in the position where a shave down seems your only solution, it means you need to adopt a better maintenance schedule.
Excellent advice. Double coated dogs do require maintenance. Blowing out the undercoat with a strong cool dryer after using a double tinned rake really makes a difference. My Tibetan mastiffs and Kuvasz did fine in high heat if they had access to water (sprinkler, child swimming pool and shade). When my Kuvasz had a disease which made overheating dangerous, we tried giving her a 1" puppy cut. It made no difference. I think she was cooler before.
If you read information from breeders of double coated working dogs, all I have seen does not recommend shaving or cutting the coat. The exception might be for a severely matted coat, but this shows a lack of maintenance.
The coat protects from insects, sunburn and in the event of an altercation with a predator, the coat also can save a dog from being hurt.