>>111148265The first book is one of the all time classic animal adventure stories along the lines of Watership Down (less bloody, but with some frightening implications). Pongo is immensely based. Perdita from the movie is actually based on the character Missis from the book while the novel's Perdita is a lost liver-spotted dalmatian brought in to help wet nurse the puppies. Cruella is heavily implied to have real demon ancestry.
The second book takes a sharp left turn and deals with the Cold War and looming threat of nuclear annihilation, adult Cadpig is the Prime Minister's pet and political leader of the dogs of the UK and the alien dog god Sirius makes an appearance. Everything sorts itself out in the end so it's fine.
TL;DR: they're pretty good