I sit up and watch my dogs work a carpetmill and a slatmill most of the time. Put that alongside some flirt pole and sling pole work along with sprinting with 20lbs of extra weight, and I can afford to sit up and give the dog an extra day of rest if it's raining like 9 hells outside.

CYJ says it best. Too many days in a row will put your dog at a disadvantage. You don't have to walk the dog in the rain to get some work put in. Walking a dog is fine and good, but it's not gonna be a determining factor in a win or lose situation if it doesn't get walked for a couple of days.