This one was almost uttered and then held back, apparently realizing it was wrong. It is a nice mashup of “barking up the wrong tree” (to attempt a futile course of action) and “backing the wrong horse” (to support a person in an effort that fails). Both phrases involve failure, and “barking” and “backing” sound and look similar, hence the mix up. Also, the word “wrong” is in each idiom, contributing to the mental hiccup. As I have posted previously, idioms involving horses for some reason are frequently mixed up, causing malaphors. Go to the Malaphors web page and search “horse”. You will find a treasure trove of malaphors. As Kramer would say, “Giddyup!” A big thanks to John Kooser for almost belching out this one.
This is a blend of “rub the wrong way” (irritate someone) and “barking up the wrong tree” (wrong about the reason for something), resulting in perhaps embarrassment to the speaker. A rubber tree image or thought might also be in the mix. A special thanks to Allen Muir for sending this one in!
This is a conflation of “barking up the wrong tree” (making the wrong choice) and “up a blind alley” (at a dead end). The confusion seems to lie in the shared word “up”, and that both idioms describe frustration and negativity. “Right up my alley” may also be in play here, juxtaposing wrong and right. And lets not forget those dogs that bark incessantly in alleys.