“Where should you never take a dog?”/“To the flea market.”

A flea market riddle is:
     
Q: Where should you never take a dog?
A: To the flea market.
     
The joke was printed in the Los Angeles (CA) Times on February 9, 1998.
   
“What happened when the dog went to the flea circus?”/“It stole the show!” is a related riddle.
   
   
Wikipedia: Flea market
A flea market (or swap meet) is a type of street market that provides space for vendors to sell previously-owned (second-hand) merchandise. This type of market is often seasonal. However, in recent years there has been the development of ‘formal’ and ‘casual’ markets[3] which divides a fixed-style market (formal) with long-term leases and a seasonal-style market with short-term leases.
     
Newspapers.com
9 February 1998, Los Angeles (CA) Times, “Pint-Sized Punch Lines,” pg. E4, col. 3:
Where should you never take a dog? To the flea market. (Joey Liberman, 7, Tarzana, Woodland Hills Elementary)
 
Newspapers.com
11 January 1999, Sacramento (CA) Bee, “Humor,” pg. C2, col. 2:   
Where should you never take a dog?
To the flea market.
 
Google Groups: alt.humor,puns
Puns of the Weak 01-02-04 Part 2 The Puns
Stan Kegel
Jan 3, 2004, 3:04:40 AM
(...)
Where do dogs go to get fleas?
To the flea market (Betty Debnum)
     
Google Groups: alt.humor,puns
Jest For Kids Weakly 03-16-04
Stan Kegel
Mar 20, 2004, 10:04:50 AM
(...)
Where should you never take a dog?
To the flea market. (Jo, 8)
   
Twitter
Dog Story
@DogStory
Where should you never take a dog?——-A Flea Market…
3:47 PM · Apr 18, 2009·Twitter Web Client
   
Twitter
Vetritionals
@Vetritionals
Where should you never take a dog? Answer- A Flea Market!
7:00 PM · Sep 29, 2010·Hootsuite
   
Twitter
Buddy The Rescue Dog
@Buddy2theRescue
Q: Where should you never take a dog? A: The ‘‘flea’’ market. #dogjokes
3:45 PM · Jan 22, 2012·Hootsuite
 
Google Books
Hysterical Dog Jokes to Tickle Your Funny Bone
By Felicia Lowenstein Niven
Berkeley Heights, NJ: Enslow Publishers, Inc.
2015
Pg. ?:
What place should you never take a dog?
To a flea market.
   
Google Books
Laugh Attack!:
The Biggest, Best Joke Book Ever
By Highlights
Columbus, OH: Highlights for Children
2016
Pg. 27:
Where should you never take a dog?
A flea market.
 
Reddit—Dadjokes
Posted by u/TheNefelivata November 15, 2019
Where should you never take a dog shopping?
The flea market
 
Twitter
Jimmy RevJim Olsen
@mybuddyjimmy
Where should you never take a dog? The flea market. #LaughoftheDay
8:12 AM · Mar 29, 2021 from West Des Moines, IA·Twitter for iPhone