sick as a dog

To be sick as a dog means to be very ill and is a way to show exactly how sick you are. The origin of this phrase and why it is referred to as being sick as a dog is not vastly agreed upon, except for the meaning. The majority of people who use this phrase understand it to mean that you are very sick to an extreme degree where you just dont feel like yourself and cant do much other than get rest and hope to get better soon.