The deaths of more than 100 dairy cows at a Jersey farm was most likely caused by botulism, according to the island's government.
The cattle at Woodlands Farm, St Helier died from an unknown cause in December 2022.
Animal tissue samples taken by the farmer’s private vet were sent for analysis immediately after the incident.
A number of possible diagnoses that can cause high mortality in cattle were quickly ruled out, including anthrax and BSE.
Now Jersey's Chief Veterinary Officer, Susana Ramos has announced that the government's main theory behind the deaths was botulism.
"It’s characterised by progressive muscle weakness," she said on Wednesday (15 February), "Cattle are extremely sensitive to the toxin, and in most cases it is fatal."
Botulism is notoriously hard to test for, and diagnosis is often based primarily on the clinical signs and by ruling out other possible causes.
Ms Ramos continued: “Despite no toxin being found, there was the presence of bacterial spores.
"We believe that these results, coupled with the exclusion of notifiable diseases, and the signs reported at the time at the farm, all combine to suggest botulism as the most likely cause of death.”
Jersey's Director of Natural Environment, Willie Peggie added that the government had been able to rule out a number of causes by a process of elimination.
"But we have not been able to identify the toxin," he said, "We were aware from the outset that a conclusive laboratory result might not be achievable.
“We have no reason to believe that there is any further risk to animals, or any risk to the general public.”
