My dog is never sick so I needed to look the expression and this is what I found: It took me awhile, but I finally found it. It's "sick AS a dog," not "sicker than a dog." As soon as I found that out, it was simple: Because dogs eat just about anything they find, they often get sick. So it's fitting to describe someone who is not feeling well as being "sick as a dog." Arf! Anyways, apparently my rheumatoid arthritis fuels any infection due to its inflammatory nature... So I manifested a sinus infection in half a day! I went from kinda ok to sick AS a dog by nighttime!!! On top of getting a steroid shot and antibiotics I'm still sucking down uber healthy smoothies although the blender sound doesn't quite agree with the sinus pressure headache... I hope all of that plus tea and spoiling from my husband and mother-in-law will help! Otherwise feeling ok- I have had a normal mammogram and ultrasound despite severe breast pain lately- ...