(USA) (US Southern) This is a response given to an unnecessary question for which the obvious answer is yes. Example: If you were to ask an Olympic archer whether she could put an arrow in an apple at ten yards, she could answer: "Does a one-legged duck swim in circles?"('Do one-legged ducks swim in circles?' is also used.)
This means that you should wait until you know whether something has produced the results you desire, rather than acting beforehand.
('Don't count your chickens until they've hatched' is an alternative.)
This means that you shouldn't speak about things that could cause an argument or tension.This idiom was used in a classic episode of the much-loved British comedy series Fawlty Towers. As a consequence if you use this phrase in Britain, listeners will understand you to be referring to Germans, or just start laughing.
(USA) If we stop to kick at every dog that barks at us we will never arrive at our destination in life, because we are obsessed with righting insignifigant wrongs that should have no more effect on us then a dog that barks as we walk by.
(UK) People, especially couples, who argue in front of others or involve others in their personal problems and crises, are said to be washing their dirty laundry in public; making public things that are best left private. (In American English, 'don't air your dirty laundry in public' is used.)