LONDON - Tasty cubes of beef would tempt any dog, let alone one sitting patiently on the stand during public viewing at Crufts, Britain's premier dog show. But instead of a treat, one owner says, a deadly surprise was sewn into the meat: slug killer.

Jagger, a 3-year-old Irish setter, collapsed and died after leaving the show with a bellyful of poisoned beef, leaving his owners distraught and triggering a canine whodunit worthy of Agatha Christie.

The dog, also known as Thendara Satisfaction, died Friday shortly after returning to his home in Belgium from the Crufts show in Birmingham, England. A postmortem examination found the poisoned slug killer cubes in his stomach, said Jeremy Bott, one of Jagger's co-owners.

The only time Jagger was unattended and could have been poisoned was when he was on the stand for public viewing, his owners said - but they refused to believe that another competitor could have done such a thing.

"We can't and we won't think that this was the act of another exhibitor. If we thought this, we couldn't go on, and the last 30 years would be a complete waste," Dee Milligan Bott said on her Facebook page. "So I ask all of you to unite in finding the perpetrator who did this."

But that still leaves the question: Who would kill a dog show contestant and why?

Jeremy Bott thinks it was a case of mistaken identity. He said he believes the poisoner is someone who bears a grudge against dogs in general or the Crufts show in particular, but not Jagger himself.

In an article published in Dog World, Milligan Bott suggested the real target of the attack could have been another dog she owns, Thendara Pot Noodle. That dog won the "Best of Breed" title at Crufts, while Jagger finished second in a preliminary competition.

Police in Belgium and Britain are aware of the incident, but authorities said they have not been asked to investigate. The Kennel Club, which organizes Crufts, said it is awaiting a toxicology report on Jagger's stomach contents before deciding what action to take.