Ease into it: Sometimes your dog reacts negatively in the bathtub because something scares him. If you take it slow, you can figure out what exactly is the problem and then you’ll have a better chance of fixing it.
Make him comfortable: Let your dog play with his favorite toy or chew on a sanitized bone while he’s in the tub. That will help him feel more relaxed and docile.
Watering him down: If your dog is especially uncomfortable when you bathe him, try putting him in the tub with lukewarm water already in it. Let him get used to it a few times and then work your way up to pouring water on him with a cup. If that goes well, you can move on to a washcloth, a hose, or whatever you prefer.
Drying your dog: When your dog is nice and clean, dry him with a soft towel starting from the rear and moving up to the face. Praise your dog while you are doing so to help him feel more comfortable.
Ask a professional: If nothing seems to work, it might be helpful to ask your veterinarian what he recommends.
It may take a while to help your dog feel fully comfortable in the tub, but if you’re patient and willing to put forth the effort, bath time can become an easy and fun activity.