Henry worries about what will happen to his big dog Mudge during their visit to his grandmother's house in the country.

Henry and his big dog Mudge celebrate Henry's birthday with a piñata, a lively birthday party, and a cake shaped like a fish tank, making May first the best day ever.

When Mudge gets sick unexpectedly, Henry does all he can to make him feel better.

Henry and his big dog Mudge try to keep busy inside the house during a thunderstorm.

When Henry's cousin Annie prepares to move in next door, he and Mudge help calm her fears.

Henry, his dog Mudge, and his parents go on a quiet camping trip to Big Bear Lake, enjoying the clean smell of trees and wonderful green dreams.

Henry, his dog Mudge, and his father enter a snowman building contest at the local park and win third place.

Henry is excited when his Uncle Jake builds him a tree house but worries that his dog Mudge will not be able to enjoy it with him.

After eight weeks at Papp's Dog School, Henry's dog Mudge earns a certificate and lots of liver treats.

Henry and his dog Mudge are invited to a sleepover in Patrick's attic, where they watch monster movies, eat pizza, and enjoy a contest to determine whose dog is the best popcorn catcher.