Rick Santorum campaign honcho John Brabender said Thursday that Mitt Romney's mistreatment of the family dog 30 years ago shouldn't be the focus of the Republican primary contest, but he didn't back down from his previous criticism.

The Washington Post's Chris Cilizza asked Brabender on MSNBC if discussion of Romney's dog is fair game.

"It was in response to a question where he described Rick Santorum as desperate and said that his campaign was going to end right then," Brabender said. "And I simply said, 'Look, here's a guy who, I'm not listening to his judgment, particularly his political judgment, about when anybody's campaign is going to end.'"

"Look, I'll be honest with you," Brabender continued. "I sit there like every other American and say, 'What the heck was he thinking, putting the dog on the top of the roof?' With that said, that is not going to become the center, core issue of this campaign, nor should it. I think there are huge differences between Rick Santorum and Mitt Romney on all these other issues, and I think those should be the focus."

In 1983, Mitt Romney attached a dog crate to the roof of the family station wagon for a 12-hour drive to Canada. The dog, Seamus, suffered a bout of diarrhea during the trip. Romney hosed off the dog and the car at a service station and kept driving.

Animal rights activists and anti-Romney elements have used the incident against the governor ever since the Boston Globe first reported the incident in 2007. On Thursday, the story made the front page of the Washington Post, thanks in part to Brabender's mentioning it on CNN Wednesday. A story about Brabender's comments appeared on the front page of The Huffington Post as well.