Jim Crosby, an outspoken animal behaviorist who has trained hundreds of dogs, thinks Millan may have even committed a crime under section 597 of California's criminal code.
"Even if we let the first engagement slide as an accident," he writes on Facebook, "this documents several felony counts occurring in California at the 'Dog Psychology Center' as directed and permitted by the trainer. It may also qualify as 'baiting' under the various state and federal dog and animal fighting statutes."
As this video posted to YouTube on Monday shows, Crosby is hardly the only dog trainer outraged by Millan's tactics.
Despite legions of fans, Millan is no stranger to controversy. His approach to training has often been criticized for its focus on deterring behavior though negative reinforcement. In a 2012 episode, Millan came under harsh rebuke after a misbehaving dog was hanged by his neck during training.
As in that incident, Millan is not facing charges from the "pig slayer" episode. Nor is he facing any official sanctions. He has not released a statement addressing the controversy.