"Every dog has his day, unless he loses his tail, then he has a weak-end"

This quote by June Carter Cash is a humorous way of saying that everybody has their moment of success, but it can be removed rapidly. The expression "every canine has his day" is a saying that implies everybody will have a moment of success or glory. The phrase "unless he loses his tail" is a metaphor for losing something essential, such as a job, a relationship, or a track record. The expression "then he has a weak-end" is a play on words, recommending that the person's moment of success is brief and rapidly changed with a period of problem. This quote is a tip that success is short lived and can be removed quickly, so it is necessary to enjoy it while it lasts.