Dog behaviorist and TV personality Cesar Millan, widely known as the Dog Whisperer, is being investigated for possible animal cruelty after viewers of his Nat Geo Wild show “Cesar 911” complained about an attack on a pig by a dog, TMZ.com reports.

“L.A. County Animal Control tells us their major case unit, along with the sheriff, are currently at Millan’s dog training center in Santa Clarita, CA after numerous complaints flooded in when Millan’s show, ‘Cesar 911,’ showcased a dog attacking and injuring a pig during a training session,” TMZ reported Thursday night.

The graphic footage shows Millan apparently using the pig to demonstrate that the dog can be calm around other animals. But the dog appears to attack the pig, which is then seen with its ear bleeding.

Officials reportedly wanted to question Millan about the location and condition of the pig.