Thendara Satisfaction, known as Jagger, died after leaving the Birmingham show. His owners say he ate poisoned beef.
Co-owner Jeremy Bott said he did not think the dog was targeted, but the culprit may been acting on “a grudge against dogs or the Crufts show”.
Fellow owner Aleksandra Lauwers said they had lost “our love, family member and best friend to our son”.
Mr Bott’s wife, Dee Milligan-Bott, told BBC Radio 5 live: “I don’t believe in my heart of hearts that this was another competitor or anyone involved in the dog world. I can only imagine that it was a random act that somebody premeditated and wanted to cause total distress at the best dog show in the world. It’s not unknown for people to do things like this. He was a typical Irish Setter, totally trustworthy and so loved. We are devastated,” she said.
He said he did not believe the attack was targeted but he did not think the culprit would be caught.
He said: “They will hopefully try with the CCTV they have in the halls at Crufts but I don’t think they will be able to find anybody.”
Ms Nettleton described her family as “just devastated and beside themselves. The sensationalisation that the media has portrayed today – that Jagger was worth £50,000 – is beyond ridiculous,” she said. “Jagger, to his family, was priceless and he was also used, not only as a family pet but as pet therapy.” She said his owners took him into elderly care homes. “He would sit there and give the residents some delight in him just being around.”
‘The biggest in the world’
- Crufts is run by The Kennel Club, the UK’s largest organisation dedicated to pedigree and crossbreed dogs
- It brands the annual event as “the world’s largest dog show”
- Almost 21,500 dogs competed this year at Birmingham’s Genting Arena, among them 2,987 dogs from overseas
- The show began in 1891
- Knopa, a Scottish Terrier, was awarded the prestigious Crufts Best in Show title on Sunday
Ms Lauwers wrote on her Facebook page: “To person who has done it, hope you can sleep well knowing you have killed our love, family member and best friend to our son.”
Caroline Kisko, Kennel Club secretary, said: “The Kennel Club is deeply shocked and saddened to hear that Jagger the Irish setter died some 26 hours after leaving Crufts.
“We have spoken to his owners and our heartfelt sympathies go out to them. We understand that the toxicology report is due and until that time, we cannot know the cause of this tragic incident. ”
Vet Steve Leonard said such incidents were “thankfully rare. Obviously they have found a foreign substance in the dog’s stomach,” he said.
Human forensic techniques would probably be used to establish what the substance was, he said, as such testing went beyond what vets would normally deal with.
“Your heart goes out to the poor owner and what they must be going through,” he said.
West Midlands Police said officers had not received any complaint “at this stage” or been asked to investigate an allegation involving the death of a dog in Belgium.
A police spokeswoman said: “If, following toxicology results in Belgium, the force is formally asked to conduct inquiries into the circumstances surrounding the death of the animal, an investigation will take place by officers in conjunction with Crufts and the NEC.”