It is a Jack Russell terrier pup, called Skipper. Now he has a friend that helps him make others, including the prettiest girl at school and the gang that used to make fun of him.
Dink goes off to fight and returns in disgrace.
Willie learns about loyalty and trust and how nothing stays the same. Except everything does, which is part of the problem. Coloured folks are well-behaved and know their place. Dink comes good in the end, as you guessed. Dad learns to like Skip, even to smile.