Depends on what you mean by shearing. Took the heavy coated collie mix and springer mix to the groomer for a summer haircuts. She left the hair at a length that they could run through the weeds, encounter sun and bugs, and manage as well as the short-haired terrier mix. The added plus was that they could do this, but before the haircut, they were as eager to move as we would be wearing our winter coats. Another added plus was being able to moniter for ticks and things. Shaving (removing the hair down to the skin level) a dog is terrible, as it exposes the skin to all the elements and bugs. Mother nature did not intend for dogs to have long fur--people did that. If your dogs are well socialized so a stranger can handle them to bathe and brush, would recommend most highly summer haircuts. If not, be sure they have cool places to go, plenty of fresh, cool water, damp places to dig in, a kiddy pool, and lots of brushing. Neighbor's GP died of heat exhaustion while they were at work--spilled his water and had dappled but not heavy shade.