What’s the Origin of “Sicker Than a Dog”?

Since Friday, I’ve been sicker than a dog. Coughing, fever/chills, sore muscles, little appetite. And not having any solid sleep, including a 48-hour period of no sleep. Yuck.

As to the origin of the phrase, DuckDuckGo to the rescue:

The earliest known usage of "sick as a dog'' dates back to 1705. It has been suggested that the phrase originated from the fact that dogs, being domesticated, are the most common animal we've seen vomiting besides ourselves. Our intimate relationships with dogs have also allowed for many other "dog'' phrases like "every dog has his day'' and the straightforward "you can't teach an old dog new tricks.'' British English has sometimes employed similar phrases involving other animals - "sick as a horse'' and, yes, "sick as a cat'' - but "sick as a dog'' is the only choice in American English.
A surprising variant that has become popular in Britain in the past several decades is "sick as a parrot,'' which typically describes someone who is very disappointed or disgusted rather than physically sick. Parrots aren't especially known for being either sick or disappointed, and no one knows exactly how this phrase originated. (One theory traces it to a famous Monty Python sketch involving a dead parrot.) It was first recorded in 1979, and it has been popular in the years since, especially among British athletes describing their extreme disappointment over losing a match.
(Source)

I’ve been so sick that I haven’t been able to post (and the low quality of this lame post suggests that I should have waited a bit longer). Even curating has been a struggle. I’ve been reduced to upvoting some of the accounts that I follow without even reading the posts. And some easy peasy upvotes for @sbdpotato

Meh. I’m going back to bed.