The devastating effects of the sheep-aborting disease Salmonella Brandenburg have been reinforced in a recent survey by VetSouth.
Fifty-five surveys were completed by VetSouth clients in Southland and West Otago, with 38% of the farmers having had instances of abortion and more than 75% of those farmers attributing it to Salmonella Brandenburg.
The aim of the survey was to get a broader outline of what was happening in the area - how widespread the disease was, how farmers were coping with it, whether they were vaccinating against it and what results they were getting from vaccinating, Gore-based veterinarian Rebecca Vallis said.
Not only did the disease cause abortion but it also made ewes seriously ill, with several farmers reporting losses of between 100 and 180 ewes.
Coupled with the fact that it often occurred in twin-bearing ewes, it was having a "huge" economic impact, particularly for southern farmers who had lost large numbers of lambs in the storm last September.
It was "gutting" for farmers to not only have to pick up aborted lambs from their paddocks, but also to deal with ill ewes.
Since initially being found in Canterbury, Salmonella Brandenburg gradually moved south, but not north. The reason for that was not known.
It was very infectious and spread easily between flocks, with black-backed gulls being a major culprit.
The majority of surveyed farmers who vaccinated their ewes had not had not had their flocks affected by the disease. Vaccination, while recommended, was not 100% reliable, because so many other factors were involved.
It was recommended that farmers vaccinate a month before the risk period and, for most farms, that meant June-July.
Stress also had an impact - if a sheep's immune system could not cope then it was more susceptible to the disease - so reducing stress on animals was advised.
The survey had given VetSouth more insight into what was happening in the area and a base for building on, Ms Vallis said.