If your dog is a large breed, you might remember the days when you put your fluffy little pup in the bathtub and bathed him. Life was easy then when you could pick him up, lift him into the tub, wash, and rinse him with swift movements, dry him, and lift him back out of the bath. But then he grew up and now getting him into the tub is impossible.
You can still keep your big dog clean while at home. You may have to get creative and give up the idea of using the bathtub, though. Summer months might allow for outdoor baths using the hose and some refreshing cool water. Inside you can consider putting your large dog in the shower with you, so he doesn't have to maneuver his massive body over the side of the bathtub, and you don't have to handle him as much as you did when you used the tub.
If your large dog remembers his time in a bathtub when he was small, he might not quite understand why you're bathing him the way you are now. Just remember positive rewards for positive behaviors keep him in check, and encourage him to continue being a good boy while you're getting him clean.