Most dogs will not soil their sleeping environment. When a dog pees in his crate, something is amiss. His former environment may have been unclean, he may be stressed, he may lack a consistent schedule, or the crate may be too large. Regardless of the situation, observation and consistency will help you eliminate the problem.
Examine the crate. The crate should be large enough for him to stand, sit and turn around. If there is enough area for him to move to the back of the crate, he may relieve himself in the back and sleep in the front. If the crate is wire, it may not give him enough comfort. Consider a plastic crate that is more enclosed. Make sure he has a blanket for comfort. Always keep the crate clean. If he pees, thoroughly clean the crate right away.
Keep a schedule. The first thing in the morning, take him out to the same spot to pee. Use the same phrase and praise him when he pees. Take him out after he eats and after playtime. Watch for when he pees. If he pees two hours after entering the crate, take him out 15 minutes earlier. Your pet will soon learn that there is a special place for him to pee.
Make sure your pup is tired and calm before putting him in his crate.
Give him a chew toy or treat for the crate. Dogs do not like to soil near the area of their food. You may even consider feeding him in the crate so he can associate the crate with food.