Apparent vascular hypertension associated with Amoebic Gill Disease affected Atlantic salmon (Salmo salar) in Tasmania

The dorsal aortic (DAP), ventral aortic (VAP) blood pressures and heart rate were measured in Atlantic salmon affected with AGD in a clinical outbreak. DAP and VAP were high compared with published values for other salmonid species. Fish subjected to a 3-h freshwater bath and returned to seawater (the treatment of choice for AGD control) had a significantly lower dorsal aortic pressure, with values comparable to those for other salmonids. Heart rate was not affected by freshwater exposure. These data suggest that there may be a vascular hypertension associated with AGD in Atlantic salmon. Although the source of the hypertension remains to be identified, this finding may help to explain the poor post-stress survival of AGD-affected salmon.