“I went to a zoo and it had only one animal—a dog. It was a Shih Tzu”

“I went to a zoo the other day and it had only one animal—a dog. It was a Shih Tzu (shit zoo)” is a popular joke that has been printed on many images. The joke has been cited in print since at least November 2005.
 
   
Wikipedia: Shih Tzu
A Shih Tzu (English: /ˈʃiːtsuː/; Chinese: 西施犬; pinyin: xīshī quǎn), also known as the Chrysanthemum Dog, is a toy dog breed, weighing 10–19 pounds (4.5–8.6kg) when fully grown. The exact origins of the breed are unknown, but it is thought to have originated in Tibet and then been developed in China.
 
Surfing Waves
The Rubbish Joke Thread!!
Post by sinistapenguin » Mon Nov 14, 2005 12:43 pm
Here’s a rubbish joke or 3 that I heard this morning - don’t you love e-mail:
 
1. A man goes to a zoo, when he gets there, there is only one animal to see and it’s a dog!
It was a Shitzu!
   
Google Groups: uk.rec.cycling
Re: OT: odd nicks WAS Re: Winter cycling gear
Ambrose Nankivell
11/16/05
(...)
It is indeed possibly the poorest pun of the week, but I did hear this one earlier on, and feel the need to share it:
 
Did you hear about the zoo that had only one animal, which, to make matters worse, was just a dog.
 
Apparently, it was a shitzu.
 
Google Groups: uk.rec.motorcycles
Is it Friday yet?
Champ
11/24/05
If so, have you heard about the man who went to a zoo?
It only had one animal in it. 
It was a dog. 
It was a shitzu
 
Twitter
ʎǝʞıɯ
@myqal
A man goes to a zoo, when he gets there, there is only one animal to see and it’s a dog - It was a Shitzu!
9:10 AM - 7 Nov 2007
     
6 August 2010, Cape Times (Cape Town, South Africa), “Life’s a menagerie when you’re pouring tomato sauce on troubled water,” pg. 11:
She tweeted this animal pun: “There was a zoo that had only one animal - a dog. It was a Shih Tzu.”
   
Google Books
That Reminds Me of A Joke:
Outrageous News Stories that Echo our Favorite Jokes
By Andy Simmons (Humor Editor for Reader’s Digest Magazine)
New York, NY: Simon & Schuster
2015
Pg. ?:
I went to the zoo the other day. There was only one animal in it, a dog. It was a shih tzu.
 
Reddit—Jokes
There was once a zoo that only had one animal: a dog.
submitted April 21, 2015 by Chaseman69
It was a pretty Shitzu.
 
Reddit—Jokes
I went to a zoo that only had a dog…
submitted December 28, 2015 by Markymaze
It was a shih tzu.