Actually there were two peteys.... Father/Son and the circles were drawn by accident... read below from website:
http://www.pitbullsontheweb.com/petbull/pete.php
The first Pete was poisoned by an unknown assailant. His last film was A Tough Winter. One of his offsprint carried on beginning with the next film, Pups Is Pups. Currently lives in Dog Heaven.
Pete's real name was "Pal," and he was owned and trained by Harry Lucenary. The distinctive circle around his eye was originally unplanned. When the spunky pit bull made his "Our Gang" debut, a circle had been painted around his eye and would not come off.
It made sense to keep it there - it made him stand out. That circle often migrates between the right and left eye from film to film. This was obviously a dog with a lot of tricks! However, if the truth be known, there were other Petey's that were used as standins for some stunts and other duties, like close-ups.
And we all thought our lovable Petey was loyal only to the Little Rascals. Not quite! Before he signed on with Hal Roach Studios as America's favorite pooch, he appeared in a series of "Buster Brown" comedies which were sort-of low rent Our Gang films.
Daintily attired Buster found himself in innocuous misadventures along side his faithful canine companion, Tige. (Petey to you and me!) Unlike Our Gang, the series was obviously aimed at very young audiences and offered very little for adults. I have no doubt that youngsters were thoroughly entertained by Buster Brown, however.
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BTW I have one named Petey too and he's a big love bug... He has a dark patch around one of his eyes... soo cute... I wonder if I could get my DD to color our Petey... hummmm maybe not if it won't come off...