She said she had spoken up about Jagger's death not to point fingers at others within the dog show.
"I've done this to raise awareness of the heinous crime that took place in the murdering of Jagger, and to make sure that we all don't become complacent and we ensure safety and security at all times," she wrote.
"So I ask all of you to unite in finding the perpetrator who did this," she wrote. "And let's continue to produce and breed our gorgeous dogs who we are all so proud of.
Toxicology tests were being run following the veterinarian autopsy, CNN reported.
The husband of Jagger's other owner said they were devastated, the BBC reported. As part of the investigation, police would be reviewing surveillance footage.
"I can only hope it wasn't an act of jealousy by another competitor, but just a lunatic," Willem Lauwers told the BBC.