Along with 47 tigers, three lions and a panther were reported to have perished from the illness since August.
The My Quynh safari park in neighboring Long An province and the Vuon Xoai zoo near Ho Chi Minh City were both affected by the H5N1 outbreak.
An official told Reuters news agency that the animals had likely fallen unwell after being fed meat from hens who had been contaminated.
According to the Vietnamese Ministry of Health, officials are “tracking the source of the chicken to determine the cause” after two samples collected from deceased tigers tested positive for bird flu. When news contacted the zoos, they declined to respond.
