Former Ultimate Fighting Championship (UFC) light heavyweight champion Frank Shamrock is being investigated after he left one his mother’s dogs tied to a vehicle at an airport for five days.

On Thursday, Shamrock – who was under UFC’s contract for 20 years – admitted in an interview with ABC-affiliated WFAA he did tie his mother’s pet dog, Zelda, to the back of a pickup truck with some food and water and left it at the Dallas Love Field Airport in Texas, on March 2, before flying back to California. The dog was found by authorities five days later.

"They can charge me with whatever. I will show up,” Shamrock said. “It is what it is. I'm not hiding in any way. It's an unfortunate and terrible thing. I'm an animal lover and I ran away crying. It’s an old dog – no one wants a 6 1/2, 7-year-old dog with a goofy hip.”

Shamrock had flown to Dallas to help his mother move out of her home. At the time he said that he found a shelter who agreed to take in one of his mother’s dogs but none of them wanted to take in Zelda. So as a last resort, he went on Facebook and tried to find a home for Zelda.

“Need help! Can anyone take a dog today in Dallas Texas?” Shamrock posted on his social media account March 2. “My mom has to give her dogs away as she can’t care for them anymore. We will be at Dallas Love Field AirPort by 4pm and flights at 5pm. Dog lovers please help Zelda is a great guard dog and she has protected my mom for years. I have called every shelter and no kill pet center within 200 miles. Now I have to fly home and need some help.”

However, he did not have any luck. "It's an old dog – no one wants a six-and-a-half, seven-year-old dog,” Shamrock said. "Here is what I guarantee. That dog is alive and safe right now and I couldn't guarantee that before I tied that dog to the truck and left."

According to Dallas police, Zelda was left tied up in the vehicle from March 2-7. The state’s animal control currently has possession of the dog. It was not immediately clear what Zelda’s future holds. Charges have not yet been filed against Shamrock.

Meanwhile, animal activists were outraged by the former martial artist’s behavior. “That weekend it was extremely cold so the dog could freeze, low temperatures, a number of things could have happened to the dog,” activist Meg Sherman told WFAA.

Shamrock officially retired from all forms of mixed martial arts June 26, 2010.