It is NOT recommended that the undercoat of a dog be shaved. Shaving the undercoat can cause the fur to grow back in patches, not to grow around the same texture or color, or the fur may not grow back at all. The undercoat is necessary to protect the dog from both hot and cold weather. Without their undercoat, they are subject to the elements. If your dog has a double-coat, we recommend leaving the brushing and trimming to the professional dog groomers.