A highly contagious viral and bacterial infection is responsible for the deaths of at least 72 tigers at two wildlife parks in Thailand’s Chiang Mai province, authorities reported on . The outbreak, which began in early , has prompted a quarantine, disinfection efforts and ongoing investigation into the cause and potential spread of the disease.
Preliminary testing identified feline parvovirus, also known as feline panleukopenia, as a primary factor in the deaths. Further analysis also revealed the presence of canine distemper virus (CDV) and Mycoplasma spp bacteria, complicating the clinical picture. According to officials, influenza A virus was not detected.
Understanding the Viruses and Bacteria Involved
Feline parvovirus is a highly contagious virus that attacks the digestive system and immune system of cats and other felines, including tigers. Symptoms include vomiting, bloody diarrhea, fever, lethargy, and loss of appetite. It is often fatal, particularly in young animals.
Canine distemper virus, while typically affecting canids like dogs, foxes, and wolves, can also infect large wild cats. CDV attacks the respiratory, gastrointestinal, and nervous systems, leading to pneumonia, neurological signs, and potentially death. The presence of CDV in these tigers is concerning, as it suggests a weakened immune state within the captive population.
Mycoplasma spp are bacteria that can cause respiratory infections, often exacerbating existing conditions. In combination with the viral infections, these bacteria likely contributed to severe pneumonia and increased mortality.
Challenges in Detection and Treatment
Somchuan Ratanamungklanon, director of Thailand’s Department of Livestock Development, explained the difficulties in managing this outbreak. “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,” he stated. This delayed detection underscores the challenges of monitoring health in large, wild animals in a captive setting.
The disease progression in tigers can be rapid, and treatment options are limited. Unlike domestic animals with whom veterinarians have frequent interaction, tigers exhibit subtle early symptoms, making timely intervention difficult.
Containment and Prevention Efforts
Authorities have implemented several measures to contain the outbreak. The Mae Rim site of Tiger Kingdom has temporarily closed for a 14-day period. Remaining tigers have been relocated to a nursing center in Mae Taeng district for quarantine and care. Strict disinfection protocols are being followed at both facilities, and officials are preparing vaccinations for the remaining tigers to reduce the risk of further spread.
The Department of Livestock Development has stressed that CDV is not a zoonotic disease, meaning it cannot be transmitted from animals to humans. There is no public health risk associated with this outbreak.
Contributing Factors and Concerns About Captive Breeding
Investigators are also examining potential contributing factors to the outbreak, including the possibility of inbreeding within the captive tiger population. Inbreeding can reduce genetic diversity and weaken the immune system, making animals more susceptible to infections. The Department of Livestock noted that inbreeding may have weakened the tigers’ immunity and increased their risk of infection.
The incident has also drawn criticism from animal rights organizations. PETA Asia stated, “These tigers died the way they lived – in misery, confinement and fear.” The organization argues that the demand for tourist interactions with big cats creates conditions that are detrimental to animal welfare and increase the risk of disease outbreaks. They suggest that reducing tourism to these facilities would decrease their profitability and potentially prevent future tragedies.
Timeline of the Outbreak
According to the Protected Area Regional Office 16 (Chiang Mai), the deaths occurred between and . to : 21 tigers died at the Mae Rim site and 51 at the Mae Taeng site, bringing the total to 72.
The authorities are urging the public to report any unusual animal illnesses or deaths to local livestock authorities immediately to facilitate rapid response and control measures. The situation remains under close monitoring as officials work to prevent further spread of the disease and protect the remaining tiger population.
