Cardiomyopathy syndrome: A multi-task approach to reduce losses and improve knowledge

Cardiomyopathy syndrome (CMS) is a severe cardiac disease in farmed Atlantic salmon. The disease has been diagnosed in Norway since mid 80s. CMS causes significant losses for the industry in the form of mortality at seawater sites and in connection with transport to the slaughter houses. As CMS generally affects large fish, the economic losses may be substantial, even though the cumulative mortality may not be very high. However, the biomass losses are substantial since the fish are mostly above 3 kg. I n the first half of 2007, the accumulated CMS related biomass losses for Marine Harvest Norway (MHN) were 1200 tonnes. Based on MHN, representing ~25% of Norwegian salmon production and assuming that MHN losses reflect an average of whole industry, overal l losses for Norwegian salmon industry can be estimated to >200 mill NOK/year. The CMS diagnosis is presently based on observations of clinical signs, autopsy and histopathology due to the lack of knowledge on aetiology, and the need to distinguish bet ween CMS and differential diagnoses such as heart and skeletal muscle inflammation (HSMI) and pancreas disease (PD). To comply with the CMS disease a multi-task project is suggested. The industry needs to find efficient methods for control and preventio n of future outbreaks of CMS. This will be pursued by identification of risk factors associated with CMS by conducting epidemiological studies together with specific experiments that are aimed at nutritional and environmental risk factors. The mechanisms underlying the pathogenesis will be described, and improved diagnostic tools will be developed to improve differentiation of related cardiac pathologies and allow for early diagnosis. Based on this work the project will aim to identify causal factors lead ing to the development of CMS, improve diagnostic tools and suggest strategies for prevention and control to reduce the occurrence and consequences of the disease.