It refers to being extremely sick. The idiom compares a human's very uncomfortable illness (like the flu or a bad virus) with how ill a dog gets when it eats something it is not supposed to eat and often gets a very severe reaction.
working like a dog
This particular idiom being in evidence since about the 1500s according to the Cambridge dictionary of American idioms. The saying "as sick as a dog" has its origins in the fact that dogs will willingly eat almost anything and be very ill afterwards. (indeed often eating the very evidence of their being ill soon after they produce it.)
It just means you're VERY ill.
"To be" is not an idiom - it's a verb.
Sick Em!
A hound is a hunting dog. If you "hound" someone, you can also be said to "dog" them -- it means you hunt them tirelessly, following after them and usually bothering them.
Pest is not an idiom. It's a word.
The popular idiom "every dog has its day" refers to the idea that everyone, regardless of wealth or previous luck, will have good things happen to them at some point. "Every dog has it's day" is another way of saying that everyone has a moment of triumph or success. The implication is that even a lowly dog has one time when everything is going it's way. The expression is a semi-quotation from Shakespeare's Hamlet: "and dog will have his day"
This is not an idiom. The idiom is "her BARK is worse than her bite" which is a dog reference meaning that she and the dog make a lot of noise but aren't really dangerous. This sentence seems to mean that she has an injured shoulder which is worse than a bite that she also has.
The idiom "apple shiner" means the teacher's pet.
The meaning of the idiom in the pink of health means being in good health.
1. This is not an idiom - an idiom is when you cannot figure out the meaning of the phrase by just defining the words. You can figure out what this phrase means by the words and context. 2. It's not pugs, which are a type of dog. It's WHEN PIGS FLY. 3. You use this phrase whenever you think whatever something is not at all likely to occur