Keeping Nipper also allows Palmer to befriend Dorothy, a girl who was his childhood best friend, and also opposes the pigeon shooting festival because of its cruelty toward the birds.

Wringer was praised by critics for its ability to address deep issues for middle schoolers, as did its precursor, Maniac Magee.

In a School Library Journal review of Wringer, Tim Rausch cited the novel for "Humor, suspense, a bird with a personality, and a moral dilemma familiar to everyone," characters who are "memorable, convincing, and both endearing and villainous," and a "riveting plot."

Suzanne Manczuk, writing in Voice of Youth Advocates, commented that "Spinelli has given us mythic heroes before, but none more human or vulnerable than Palmer."

New York Times Book Review critic Benjamin Cheever also had high praise for Wringer, describing the novel as "both less antic and more deeply felt" than Maniac Magee, and adding that Spinelli presents Palmer's moral dilemma "with great care and sensitivity.