One thing you can do is take his books and add instrumentation to them. Taking the rhyming words and adding different instruments to them makes reading the book really fun and the students will really focus on the story that is being told as they anticipate their part. It is fun to get them to explore the instruments first and see if they can match sounds with the words. Having them pat the beat on a drum as you read through the book is great if you are working with those primary students on internalizing the beat. Then having them move on to playing a different instrument for the rhythm of the words so they can compare and contrast the steady beat vs. rhythm/syllables can expand it even more. Having half the class do the beat while the other does the rhythm is great, too.
If you want to have them doing large locomotor movement, have them march to the beat as you read the stanza. At the end of the stanza they have to freeze. Read the stanza again and have them creatively move their body in a different way to help tell the story. Freeze again and go back to the beginning and have them just walk to the beat as you read it. Then have them tell you which way they enjoyed the most (#1 moving, #2 expressively moving, or #3 the beat). There is no wrong answer but they should explain why they liked that way better than the others. It will help them get in tune with the music in the books (typically the rhythm and beat) but also learning about how their body can move to the rhythm & beat).
Obviously, creativity was key in any of his books and so anything you can think of that is outside of the box yet inside of what we do as music educators can be great fun for all involved. Have a great Dr. Seuss week!!!