The inside of our kennels are swept and mopped everyday with cleaner and disinfectant. Bedding is changed as needed and after every dog leaves. Your dog will always be coming in to sleep on clean bedding that has not been used by another dog.
As you can see from the pictures below, we have guillotine doors that lead to the outside runs. If the weather is nice, we hook the doors open, so the dogs can go in and out as needed. If the weather gets hot enough to need the air conditioning turned on or cold enough to need the furnace turned on, we close the doors and let the dogs out to use the bathroom periodically throughout the day.
There is a pallet in each run with bedding on top of it, so no dog sleeps directly on concrete, unless they choose to.