Following the discovery of dozens of dead cattle in the buffer zone area of Koshi Tappu Wildlife Reserve, conservation officials are concerned that the mysterious disease could spread to the reserve’s wildlife and threaten their lives.

The Department of National Park and Wildlife Conservation, the government body that manages protected areas and wildlife, dispatched a two-member team to the reserve on Sunday to study and prepare a report. The place where the cattle were found dead is less than 700 metres from the reserve’s forestland.

Technicians at the Livestock Disease Research Laboratory in Biratnagar who conducted a test on the dead cattle said they had detected anthrax. Officials said at least 44 cows and oxen were found dead in Srilankatapu on Thursday, bleeding from their nose, eyes, ears, mouth and anus.

“The lab test confirmed that the cattle died due to soil-borne anthrax bacteria. The disease is transmissible in nature through air, water, and soil,” said Dr Manoj Kumar Mahato, a veterinarian at the Inaruwa-based Veterinary Hospital and Livestock Service Centre.

However, officials at the national park department refused to declare that the disease that killed the cattle was anthrax.

“After the laboratory reports said anthrax was detected, we have immediately dispatched a team on the ground,” said Bishnu Prasad Shrestha, a spokesperson with the department. The team is expected to take notes from local residents, veterinarians and other park officials during its investigation.

“So far, we have only heard of this outbreak in domestic animals but we can’t confirm that until our team makes the assessment on the ground,” Shrestha said.

Anthrax is a highly infectious bacterial disease found in sheep and cattle and is transmissible to humans. The infected animals die within a few hours of the infection.

According to Mahato, they have asked provincial and local authorities to dispatch vaccines to the local community.

“Vaccines should be administered at the earliest because the disease could be easily transmitted to humans and other animals,” he said.

Some conservationists are concerned that wild water buffaloes, locally known as Arna, are also vulnerable to the bacteria.

Arna is mentioned as an endangered species—there are 3,400 of them in the world—on the International Union for Conservation of Nature Red List. There are an estimated 10,000 other animals and stray cattle and buffaloes in the reserve.

Ramdev Chaudhary, chief conservation officer at the reserve, said they are mobilising skilled human resources to contain the disease. But he admitted that it is highly challenging to administer vaccines against anthrax to animals in the reserve.

“We haven’t found other dead animals in the area in the last four days,” said Chaudhary, who inspected the affected area on Sunday. “We are coordinating with other authorities to find ways to contain the disease—by using fire, and spraying medicines and lime powder to eliminate the bacteria.”

Wildlife experts have also warned that because of the close proximity of human settlements to the reserve, there are chances of interspecies breeding between domesticated water buffaloes and indigenous wild water buffaloes, potentially threatening the latter.

The Koshi Tappu Wildlife Reserve was the only natural habitat of wild water buffaloes in the country until wildlife authorities, in an attempt to create a new protected area for Arna, translocated 13 of these endangered buffaloes to Chitwan National Park in 2017.