There have been reports that up to six dogs may have been poisoned at this year's Crufts show.
A West Highland white terrier, an Afghan Hound and a Shih Tzu were sick after the show, according to reports.
It comes as the co-owners of Jagger, the Irish Setter which died after allegedly being poisoned in a "heinous crime" at Crufts, vowed to continue competing in the world famous dog show.
Crufts said speculation about "other incidents involving other dogs" are, at this stage, "just rumours" - but said sabotage will not be tolerated and anyone who puts a dog's welfare at risk could face prosecution.
Mylee Thomas's Shetland Sheepdog, Myter Eye to Eye, is thought to have been poisoned the day after the Irish Setter was allegedly killed.
Ms 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."