The survey was carried out by the National Veterinary Institute and commissioned by the Swedish Board of Agriculture. The results do not show that the animals are infected, but that they hit the bacterium. In previous surveys from 2013, Gotland's values ​​were 5.5 percent - a figure that was then close to the national average.

- At present, it is not possible to say how the herds got in contact with the salmonella bacterium. It is common for the bacteria to spread through water, feed, pests or when purchasing animals. What lies behind the elevated values ​​at Gotland cannot currently be answered, says Agneta Karlsson Norström, who is county veterinarian in a press release.

At present it is unclear why the Gotland dairy farms have elevated levels of antibodies to salmonella.

- In order to answer this question, further investigations are required, which will be conducted during March-April, says Agneta Karlsson Norström.