RMS first appeared in Scotland and the south of England in 2004, but is now virtually endemic, according to Fish Farming Expert.
Aquaculture feed producer, Skretting, organised a one-day symposium for trout farmers to exchange information, hear of recent farm experiences and the latest research progress and control methods.
Chaired by Hamish Rodger of Aqua-Vet International, an advisor to Skretting, the meeting included reports by trout farmers, academics and speakers from fish health companies.
Robert Hughes, the Skretting trout sales manager, gave the opening presentation. He underlined the serious economic impact the condition can have for farmers:
“Although the large red blotches are generally only skin deep, their presence leads to high rejection rates from processors, a problem that is compounded by the fact that the outbreaks usually occur among fish close to harvest weight.," he said.
"The farmer can wait until the fish recover naturally, which can take a few weeks, or treat with antibiotics, but then is faced with the statutory withdrawal period, again of several weeks," Mr Hughes explained.
"Either way, the impact on farm income can be significant. It tends to be worse in cool summers and we have just had two in succession. RMS was possibly the most significant disease problem for trout farmers in 2009.”
Among the research reported was the work partially sponsored by Skretting at Stirling University. This indicates the causal organism is probably a flavobacterium.
Red Mark Syndrome in Trout
UK - Red Mark Syndrome (RMS), a condition that is increasingly seen on trout farms throughout mainland Britain, was discussed at a recent industry one-day meeting.