Nobody knows for sure what is so special about dogs’ meals, but if someone uses “dog’s dinner” in a conversation with you,
he would not be trying to compare you with a bowl full of bones, meat and unidentified meat-like products. Here is what those sayings actually mean:
“Dog’s breakfast” – this phrase refers to a mess or muddle of some sorts. So, “you made a dog’s breakfast of that!” would actually mean “you really screwed this up!”
“Dog’s dinner” – the full phrase usually is “dressed up like a dog’s dinner.” This saying refers to a person who has dressed up for some occasion – or no occasion at all. Usually the phrase has a sardonic meaning, implying that the person has actually overdressed