People know what a bird dog is, but what’s a baseball dog? A joke was printed in the Milwaukee (WI) Journal on May 23, 1937:
 
Salt—I’ve got a baseball dog.
Pepper—What’s a baseball dog?
Salt—He wears a mask, catches flies, chases fowl and bets it for home when he sees the catcher coming.—Marian G. Drake.
 
“What is a baseball dog? One that chases fowls” was posted on Twitter on September 13, 2009.
   
           
23 May 1937, Milwaukee (WI) Journal, “Laughs,” Boys and Girls Section, pg. 2, col. 5:
Salt—I’ve got a baseball dog.
Pepper—What’s a baseball dog?
Salt—He wears a mask, catches flies, chases fowl and bets it for home when he sees the catcher coming.—Marian G. Drake.
         
3 April 1940, Postville (IA) Herald, “Country Correspondence,” pg. 6, col. 2:
Dear Voice of Experience—What is a baseball Dog? Ben.
Dear Ben— A dog that wears a muzzle, catches flies, chases fowls, and beats it for home when he sees the catcher coming.
 
Google Books
July 1962, Boys’ Life, “Think and Grin,” pg. 62, col. 2:
Q: What is a baseball dog?
A: One that chases fowls, chases flies, and makes a home run when he sees the catcher coming. — Billy Boyle, Manteca, Calif.
 
12 June 1966, Boston (MA) Herald, “Riddles,” magazine, pg. ?, col. 1:
What is a baseball dog?
From KARI SPRIGGS (12)
Somerville
(Col. 8.—ed.)
One that wears a muzzle, catches flies, chases fowls, and beats it home when he sees the catcher coming.
   
Google Books
Jokes, Puns, and Riddles
By David Allen Clark
Illustrated by Lionel Kalish
Garden City, NY: Doubleday
1968
Pg. 176:
Nancy: What is a baseball dog?
Clancy: Well, he wears a muzzle, catches flies, chases fowls, and beats it for home when he sees the catcher coming.
   
Google Books
Biggest Riddle Book in the World
By Joseph Rosenbloom
Illustrated by Joyce Behr
New York, NY: Sterling Publishing Company, Inc.
1976
Pg. 234:
What is a baseball dog?
A dog that wears a muzzle, catches flies, chases fowls, and beats it for home when he sees the catcher.
 
July/August 2003, Child Life (Indianapolis, IN), “Jokes & riddles,” pg. 34:
John: What’s a baseball dog?
Scotty: Well, he catches flies, chases fowls, and beats it for home when he sees the catcher coming.
 
Twitter
Bollywood Sargam
@bollywoodsargam
Dog jokes - 4189 Joke: What is a baseball dog? One that chases fowls. .... http://bit.ly/Wvktq
9:24 PM - 13 Sep 2009
   
YouTube
Ok, here is the joke. What is a baseball dog? One that chases ...
botcaster inc. bot
Published on Jan 22, 2016
What is a baseball dog?
One that chases fowls.
 
Twitter
Lucky Score
@LuckyScoreNet
What is a baseball dog?
One that chases
fowls.
#Joke from #DogJokes in #Jokes, #Humor and #Satire
12:16 PM - 21 Mar 2018