Molokai ranchers and farmers are losing livestock due to an outbreak of bovine tuberculosis, the most severe spread of the disease that officials have seen in decades.
Six different herds of cattle, swine and sheep have been found infected with the disease between June and March in the central and west ends of Molokai, with several groups being depopulated or slaughtered.
“We’ve raised, like, really nice hogs and it’s a real disappointment and upset me that this whole thing is happening. I’m devastated,” Susan Donnelly, who lives on Molokai’s west end, said Monday night after losing cattle, sheep and pigs earlier this year. “The whole farm got depopulated, we lost everything. Everything. We killed everything.”
Cattle are the primary host of the bacteria that causes bovine tuberculosis, according to the state Department of Agriculture, but it can also infect other domesticated animals, such as sheep, goats, pigs, dogs and cats, and wild species like boars and deer.
The cause of the infections remain under investigation, Dr. Jason Moniz, veterinary program manager for the Department of Agriculture’s Animal Disease Control Branch, said during a department meeting on Molokai Monday night. He added that research into the wildlife around Hoolehua and Mapulehu “is important to complete.”
“We are concerned that this outbreak is big enough that if we are not careful, we could end up jeopardizing the status of the whole state and potentially other states because we do move cattle from this state, including Molokai, to other states,” Moniz said. “This outbreak appears to be highly contagious, substantial and widespread, and may have multiple sources.”
A quarantine order was issued for Molokai on April 8 to require a permit before moving any live ungulates, except horses, to any location outside their premises due to detections of bovine tuberculosis, which is a chronic and transmissible bacterial disease of animals.
Moniz reassured that any meat from cattle, swine or deer that pass the U.S. Department of Agriculture Food Safety and Inspection Service inspection at slaughterhouses are OK for human consumption.
Those who attended the meeting in person at the Lanikeha Community Center in Hoolehua on Monday night were concerned with the department’s response, saying that quarantine and depopulation methods would literally “kill Hawaii’s cattle industry” and have severe financial impacts on ranchers and farmers.
Others questioned why the department was only responding to the issue now, arguing that there was very little communication with the public previously and wanting to meet again for other possible solutions and clarifications.
“There’s a lot of work to be done and I hear the frustration, I understand what’s going on with the producers,” said department veterinarian Dr. Isaac Maeda. “This is not anything that is simple. Kind of like Dr. Moniz is saying, we cannot be doing the same thing. We have to try and do something different.”
The meeting lasted beyond two hours while residents also asked about possible sources of the infectious spread, including the uncontrolled axis deer or rodents, the importation of feed or the ongoing drought conditions.
Though low numbers of mongoose, feral pigs and axis deer have tested positive for bovine TB on the east end of Molokai in the past, their role in this particular outbreak is yet to be determined and needs more proof, Moniz said.
“I’m so glad that you guys, for the benefit and safety of the people, are going to test feral animals,” said Jimmy Duvauchelle, who worked for Molokai Ranch for 50 years. A herd at the ranch is being considered for depopulation, or test and removal, to eliminate infection.
Bovine TB on Molokai
Historically, bovine tuberculosis on Molokai is more prevalent in feral pigs, Moniz said. In 1985, a complete island depopulation of more than 9,000 beef cattle was conducted, because at that time, it was thought that infection in wildlife would die out once infected cattle herds were removed.
Beef operations halted in 1986 while the island remained cattle-free, but slowly repopulated with steers thereafter. When all the steers were slaughtered and found free of bovine TB, breeding cattle that tested negative for the disease were allowed to be restocked.
During a wildlife surveillance survey on Molokai from 1998 through 2012, 20 infected feral swine were detected between Kamalo and Mapulehu. None of the samples from 477 axis deer, 81 feral goats or 61 mongoose tested positive.
No positive cases were detected in 25 years of annual herd tests on the east end from 1997 to 2021.
In addition, cattle slaughtered at the Molokai Cooperative Slaughter Plant or any other plant throughout the state are routinely inspected for bovine TB lesions.
In June, however, a new outbreak of bovine tuberculosis was detected in a small beef herd in central Molokai. Testing of a neighboring herd found they were also infected.
Moniz said that both infected herds were depopulated after ranch facilities were cleaned and disinfected. The quarantine orders placed on those herds ended on Dec. 22.
In November, four swine from a farm on the west end of Molokai were found positive for bovine TB when slaughtered. The premises where the swine lived also contained cattle and sheep.
The ranch was placed under quarantine and depopulated, he said. Other swine farms that were traced in central Molokai are also quarantined and depopulation is being planned or is ongoing, Moniz said.
Recently in January to March, more infected herds were detected in both the central and west end of Molokai.
Similar to testing for COVID-19 variants, Moniz said that genome sequencing has helped to provide insight to the bovine TB clusters on Molokai, such as the fact that all detections in the 2021-22 outbreak are of the Molokai strain, meaning it’s not caused by a new introduction from outside of the island.
However, sequencing shows that there may be three separate outbreaks on Molokai with different sources/introductions, he said.
And, looking at each swine and cattle herd recently testing positive for bovine TB, there are several indicators that suggest some infections happened over a long period of time, some very recently, or they contracted the disease all at the same time.
Combating the spread
Officials said they are still working to determine the extent of the outbreaks in livestock and hope to expedite bovine TB testing, contact tracing and depopulation of infected herds; ramp up testing of hunter-collected wildlife carcasses; and schedule testing for current infected herds and herds located within a 10-mile radius of infected herds.
“We’re going to end up basically testing the whole island,” Moniz said.
At the same time, the department is also seeking legislative funding for two positions, including a veterinary medical officer to lead disease investigation and control activities on Molokai full time and a full-time livestock inspector to assist with livestock testing, movement control and wildlife surveillance.
Funds are also being sought for a portable office to house two livestock inspectors and one vet, as well as to purchase a quarantine facility for handling and testing livestock and to support small farmers and ranches that do not have their own corrals.
They would also want funds to purchase feed for producers when conducting herd tests; a vehicle to move staff, equipment and livestock and buy an additional portable chute and livestock trailer.
“We know the herds that are infected, but we don’t know the status of some of the other herds and it seems like the more we look, the more we’re finding right now,” Moniz said. “The purpose is to prevent the spread of bovine tuberculosis to the rest of the state, the nation and to the rest of the ranches on Molokai that are not infected.”
* Dakota Grossman can be reached at email@example.com.