Trainer is responsible for the death of 11 dogs in the USA

This story contains graphic details of animal cruelty.

Although Miko was just over a year old, the shepherd mix had already reached its adult size. He was tall enough that his snout could reach a snack package on someone's waist; their paws, once disproportionately large, now befitted their large breed heritage.

In June last year, Miko's owner, Alexander Kostyukevich, sought training for the young dog from someone he found on Instagram. He decided to use Happy K9 Academy after a successful session with the owner, Kwong Chun Sit, aka Tony.

But just days after leaving his dog in Sit's care, Kostyukevich received a text message that would devastate any pet owner: Miko was dead.

The mysterious death of a young, healthy dog in Southern California ended up taking investigators on a morbid and disturbing journey through crematoriums, pet disposal services and a cargo van that smelled of bleach and feces as they continued to uncover more deaths.

Sit, 54, and his girlfriend, Tingfeng Liu, 24, were sentenced last week. Sit on multiple counts of animal cruelty and other charges related to the deaths of nearly a dozen dogs, and Liu on multiple counts related to his help with their cremation.

Prosecutors from the Orange County District Attorney's Office said Sit left the dogs in small cages in the back of a hot van, where they died of heatstroke, and then pretended to be their owners so he could cremate them.

The couple are expected to be punished for their horrific deaths during their sentencing scheduled for July 10. Sit could be sentenced to nearly 14 years in prison, while Liu could receive a four-year sentence, according to the district attorney.

While the families will see justice served in court, they will still have to live without their beloved dogs and come to terms with the reality of how they died.

The last traces of these pets' short lives remain on the internet, in training videos sent to families and posted on YouTube: friendly dogs, big and small, with their hind legs imitating a smile, as they followed the instructions of a man who was supposed to be their caretaker.

The text message that ended in a call to the police
The dogs Kostyukevich saw on the Happy K9 Academy Instagram page appeared happy and obedient. When he received a message from Sit on June 18, 2025, just three days after leaving Miko in Sit's care, it was a shock:

"It is with great sadness that I report the passing of Miko, who passed away peacefully during the night while resting. There were no signs of pain or suffering, and it was truly unexpected. I am deeply saddened by this loss."

"Out of respect, I will refund the full training fee and offer additional compensation. The body was cremated with utmost care and I will keep the ashes safe for you until you are ready."

"Know that I'm thinking about you. If you need anything, I'm here for whatever you need."

The message was surprising, coming from a trainer who had acquired clients through recommendations. Sit's company has had more than 40 five-star reviews on Google over its six years in business, with comments like "I couldn't be happier," "he truly cares about the dogs he trains," and "he never disappoints."

According to a court document detailing the information that would be covered in the trial, known as a summary of proceedings, Kostyukevich called Sit to obtain information about what had happened.

His immediate concern was that Sit had sold Miko, according to the document. But Sit hung up on him, and Kostyukevich decided to call the Irvine police.

Unusual death leads to discovery of 10 others
Casey Pickett, an animal services officer with the Irvine Police Department, began investigating. She called Sit and discovered that another dog in her care, Ziggy, had also died.

Pickett discovered that the animals had been collected by a service called Mobile Pet Cremations, which suspended the cremation as soon as it was contacted by police.

However, a crematorium employee informed Pickett that not only did they have Miko and Ziggy, but they had also picked up another dog from Sit just the week before. And that wasn't all: the employee said they had spoken to another pet cremation company and discovered that Sit had left two more dogs there, which meant that five dogs were now dead.

After learning of the numerous dogs abandoned at various shelters, Pickett went to Sit's home on the outskirts of Orange County, according to the trial summary.

Sit told her that only two dogs had died in their sleep during the night and that he was "very sad."

Pickett then asked about two other dogs that had been sent for cremation. Sit then confirmed that four dogs died.

"Sit stated that he went to sleep and woke up this morning to discover that all four dogs had died," the trial summary reads. He told police he used two different services "due to the high cost of cremation," according to the same summary.

Upon completion of the investigation, authorities discovered that the couple had contracted cremation or disposal services for a total of 11 dogs from four different companies.

Sit would later be convicted on 19 counts: 11 counts of animal cruelty, seven misdemeanors for attempted destruction of evidence, and one misdemeanor for destruction of evidence.

What led to the deaths of all the dogs was "a tragedy that left many dog owners sad and angry," Sit's lawyer, Kate Corrigan, said in a statement. She added that her client is "an experienced dog trainer" and that testimony during the trial demonstrated his track record and skill in dog training.

"The dogs' deaths were unexpected and did not result from intentional acts on the part of my client," she said.

Investigation into trainer's home yields stunning revelations
Although one of the dogs had already been cremated when the deaths were discovered, many of the owners and funeral services were able to postpone the cremations. A woman scheduled a wake to say goodbye to her nearly 3-year-old pitbull, whose muscular, reddish-brown body was now lifeless.

He was supposed to return home that day after three weeks of training.

A veterinarian was able to examine the remaining dogs and determined that eight died from hyperthermia and heatstroke, and one died from "blunt head trauma with acute spinal cord injury and spiral leg fracture," according to the trial summary.

Although Pickett was initially at Sit's house, she obtained permission to see Sit's black Mercedes cargo van. She reported the overpowering odor of "bleach mixed with a strong smell of feces," according to the trial report.

The next day, police returned with a search warrant for his home and cars, where they found nine boxes loose in the back of the van and a portable air conditioner spewing air out the side of the vehicle, according to the trial report. A bottle of bleach was found on the passenger side floor.

While an investigator was in Sit's apartment, news arrived of the death of another dog, raising the number of incidents to a seemingly impossible level for an establishment that, until then, had received few complaints.

According to the prosecution, Liu, Sit's girlfriend, helped take the dogs to the crematorium. During a search of Liu's Tesla, investigators found a trash bag containing a pink collar with the name "Luna," according to the trial report.

They also found a receipt from an animal disposal company with the following inscription: "1 DOG DELIVERED - PAID (US)$160.00".

Liu was convicted of complicity in a serious crime, a misdemeanor of destruction of evidence and two misdemeanors of attempted destruction of evidence. Liu's lawyer argued that "she was not the decision maker in this case."

Frederick Fascenelli said they believed there was still reasonable doubt in the prosecution's case as to whether she knew a crime had been committed and whether she tried to help Sit avoid arrest.

"The evidence demonstrated that she was a young woman, in an unknown country, far removed from the authority and control exercised by Mr. Sit, and that many of the actions attributed to her were carried out under the direction of third parties, and not as part of an independent criminal plan," Fascenelli said in a statement.

While they were disappointed with the verdict, they respect the jury's decision and are looking at their options after the trial, he said.

The dog trainer who betrayed his clients
Although Happy K9 Academy's social media showed dogs following commands and clients praising its work, authorities' investigation revealed a darker side to the company's business practices.

In May 2025, a client took her 4-year-old Belgian Malinois, named Max, to Happy K9 Academy for three weeks of training, according to the trial report. Everything seemed to be going normally, and she received regular video updates from her dog.

Six days later, Sit texted her to say that Max had a wound on his leg. She decided to take him to the vet, but when she went to pick him up, she realized that Max was in the back of the van, in a box so small that he couldn't stand upright, according to the trial report.

Max also smelled very bad, could barely walk and had around ten wounds on his body, according to the document.

Several years earlier, in 2021, another client sent her two Maltipoos, Capo and Tropez, for four-week training, according to the trial summary.

The updates she received regularly at first began to dwindle. When she asked for a photo of the dogs, Sit sent one showing them in a small box without a blanket or water. She decided to stop training and get them.

Inside Sit's van, she saw "the entire van filled with shipping crates stacked on top of each other," with the dogs panting and without access to water, according to the trial report.

Although Sit's lawyer argues that the deaths were not the result of intentional acts, prosecutors in the trial document stated that he knew what he was doing when he packed the dogs into the back of a hot van, "knew his actions were negligent and simply didn't care."

Their Yelp page still appears in online search results, but now displays the message "CLOSED - Updated June 2026."

While Google reviews hold memories of past clients sharing successful trainings, one review, written about a year ago, is a blunt reminder of what happened:

"My 8 month old puppy died while in the care of Tony Sit and 'Happy K9 Academy'. She was 100% healthy and now, 5 days after starting training, she is gone - along with a second dog who was also staying there and who mysteriously died the same night. PLEASE STAY ATTENTION."

Source: CNN