Initial laboratory findings from livestock authorities indicate that the 72 tigers that died at the Tiger Kingdom tourist attraction in Chiang Mai were infected with feline parvovirus, with secondary bacterial infections aggravating the illness.
The virus, which attacks the digestive tract and immune system, can be rapidly fatal and is known to cause severe vomiting, bloody diarrhoea, fever and extreme weakness.
The outbreak occurred at Tiger Kingdom facilities in Mae Rim and Mae Taeng districts of Chiang Mai province, where a total of 246 tigers were housed.
Between February 8 and February 18, 72 animals died — the largest mass mortality event involving captive tigers ever recorded in the country, officials said.
Veterinarians from the Chiang Mai Provincial Livestock Office who conducted post-mortem examinations also detected Mycoplasma bacteria, which officials said worsened the animals’ condition.
In addition, some samples tested positive for canine distemper virus (CDV), a respiratory disease that, while commonly associated with dogs, is known to infect large cats as well.
Authorities said inbreeding among captive tigers may have weakened the animals’ immune systems, making them more susceptible to infection. All of the diseases identified are not transmissible to humans and pose no zoonotic risk, officials added.
Following the deaths, the Mae Rim site was placed under quarantine and disinfected on Friday. The attraction has been ordered to close for at least 14 days, while surviving tigers have been transferred to a Tiger Kingdom care centre in Mae Taeng.
Officials also dismissed speculation that contaminated raw chicken meat was to blame. Department director Somchuan Ratanamungklanon said testing found no trace of avian influenza.
“When tigers fall ill, it is more difficult to detect than in animals like cats or dogs. By the time we realised they were sick, it was already too late,” Dr Somchuan told reporters.
Executives from Tiger Kingdom were not available for comment. The company promotes close-contact experiences that allow visitors to touch and pose for photographs with the animals.
Animal welfare groups condemned the deaths, renewing criticism of wildlife tourism venues.
“These tigers died the way they lived — in misery, confinement and fear,” the animal rights organisation PETA Asia told AFP.“
“If tourists stayed away, these places would quickly become unprofitable, and tragedies like this would be far less likely to happen,” the group added.
