Jimmy Kimmel and his daughter Jane. Picture: Instagram/@JimmyKimmel

A fight broke out at Jimmy Kimmel's daughter's fourth birthday party at the weekend. 

The 50-year-old television host pulled out all the stops to ensure his little girl Jane, whom he has with his wife Molly McNearney, had the best bash last week but he has admitted the festivities descended into chaos after the dog-themed pinata came out. 

Speaking on 'Jimmy Kimmel Live!', he said: "It was a terrible pinata, it wasn't even shaped like anything, just a rectangle with four dogs on it, one of which was Chase -- that's her favourite dog, Chase. 

"Finally, they crack this thing open, and the candy comes out, and they all dive in and fight each other for it. It's horrible. It's like Black Friday for kids.

"My wife notices Jane staring at what remains of this pinata that has been assaulted and beaten to a pulp by dozens of crazed, stick-wielding children ... and Jane looks at it, and says to no one in particular, 'I can't believe we beat up Chase.' 

"And then she goes -- and I don't know where she got this -- but she goes, 'Look at these guys, they never saw it coming.' "

Jimmy hasn't had the easiest of years recently as his son Billy was born with a congenital heart defect and was forced to undergo surgery at just three days old. 

He said a few months ago: "There were secrets we kept from each other that we revealed only after the second surgery.

"The biggest one was that, I think subconsciously, we didn't want to get too close to the baby, because we didn't know what was going to happen...I don't know if that's right or wrong or common or uncommon. 

"But when I told her I was feeling that way, she said, 'Oh, I'm so happy you said that because I was feeling that way too, and I didn't want to express it.' "

Billy is now doing "great" following his surgery but Jimmy - who also has kids Katie, 26, and Kevin, 24, with former wife Gina, has revealed he will still require treatment.

He explained: "He'll have another surgery when he's around six or seven years old, but in the meantime, he's doing great."