An investigation has been launched after 38 French bulldogs were found dead on a cargo flight from the Ukraine to Toronto earlier this month.
The dogs were part of a shipment of 500 puppies being transported on the flight. Those that survived were suffering from vomiting, weakness and dehydration, according to Canadian officials.
"Ukrainian International Airlines is a member of the International Air Transport Association, which has voluntary guidelines airlines should follow to ensure animals are transported safely," the Canadian Food Inspection Agency (CFIA) said in a statement.
"CFIA officials are currently investigating the circumstances surrounding this incident and will determine next steps once the investigation is complete."
A witness who was picking up their own dog from the same cargo arrival area told CBC News it was a "horror show".
"It was just a nightmare," Abby Lorenzen said.
"Canada and the federal government need to change the laws on the importation of these puppies."
Ukrainian International Airlines (UIA) has offered its apologies to those affected.
"Everyone at UIA offers its condolences for the tragic loss of animal life on our flight," the airline said in a statement.
"UIA is working with local authorities to determine what happened and to make any changes necessary to prevent such a situation from occurring again."
The dogs are reportedly imported and sold on websites such as Craigslist where they are described as being born and bred in Canada.
Experts say it's possible organised crime rings are involved in importing the popular breeds.
The 500 French bulldogs on this flight would have sold for more than NZ$3 million in total.