Six dogs were reportedly poisoned at the Crufts show where one died after eating poisoned beef, organisers have confirmed.
The Irish setter called Jagger died after eating the food at the prestigious dog show at the Birmingham NEC.
In a separate twist to the sorry saga, a petition has been launched calling for the handler of the winning dog to be stripped of the award for rough handling the dog, including picking it up by the tail.
Several other dogs including a West Highland white terrier, an Afghan hound and a Shih Tzu were also taken ill, sparking fears that one or more people may have been poisoning the dogs.
The victim, Jagger
Mylee Thomas's Shetland sheepdog Myter Eye to Eye is thought to have been poisoned the day after the Irish setter was killed. She said she thought her dog was targeted by an expert, whereas Jagger had been randomly targeted.
Mrs Thomas told the Daily Telegraph: "The setter was poisoned the day before my bitch, and I don't think there is a link between the two.
"I think that one (Jagger) was someone who had randomly targeted them because a lot of people don't agree with Crufts."
But the Kennel Club, which organises Crufts, said no other dog owners have contacted them to report suspicions of poisoning.
A spokeswoman said they are looking into the poisoning reports, but stressed that no formal investigation has been launched because there was no direct information to act on.
She said: "The facts surrounding Jagger's sad death are still being established. With regards to speculation about any other incidents involving other dogs, we must stress that these are at this stage just rumours.
"There are any number of reasons why a dog may display symptoms such as sickness and should a dog fall sick there are vets at Crufts who will examine the dog in question and file a report."
She added: "As with any international competition, rumours of sabotage do occasionally surface. This of course is not in the spirit of competition and will not be tolerated.
"Anyone caught attempting to deliberately sabotage another competitor's performance, particularly if a dog's welfare is put at risk, will face severe disciplinary action, which could include a ban on competing at all Kennel Club licensed events."
The animal's joint owners have said that beef laced with unknown poisons was found during an autopsy, and West Midlands Police is liaising with Crufts officials and the NEC to secure potential evidence.
Co-owner Dee Milligan-Bott said Jagger's death was the result of a "heinous crime", but said she did not want dog shows "to become a ground of finger-pointing and suspicion". She believes the suspected poisoning to have been a random attack.
Knopa, the Scottish Terrier, with handler Rebecca Cross (second left) after winning Best in Show
Meanwhile, more than 80,000 people have signed a petition calling for Rebecca Cross to be stripped of the 'Best In Show' award for "harsh handling" of the Scottish Terrier.
"Despite being repeatedly warned and agreeing to abide by Kennel Club rules, this handler continued to mishandle her charge by lifting the dog repeatedly by its tail and neck and repeatedly jabbing it in the ribs," the petition says.
She picked it up by the tail during the award presentation.
Mrs Cross said: "I apologised. I didn't do it on purpose, it was just habit. It's just one of those things. It happened and I tried to really think about it and not do it, but it's habit."