Cardiomyopathy syndrome in Atlantic salmon (CMS) – Histopathology

CMS in ventricle of Atlantic salmon showing severe myocarditis of spongy layer. Note that the compact layer (on the left) is largely unaffected.

Cardiomyopathy syndrome (CMS) is a severe cardiac disease affecting Atlantic salmon characterized by prolonged periods of usually low-level mortalities. The disease was first recognized in farmed Atlantic salmon in Norway in 1985 and subsequently in farmed salmon in the Faroe Islands, Scotland and Ireland. CMS is a transmissible disease that has been causally linked to the Piscine Myocarditis Virus (PMCV), closely allied to the Totiviridae. CMS usually causes mortality in adult or maturing fish after 12 to 18 months in seawater, resulting in substantial economic...


Atlantic salmon, presmolt, FW, exposed to electric shock. Note the spinal fracture associated haemorrhage. The cause of the electric shock was an energized cable that fell into the tank.

Bone is a highly anisotropic, viscoelastic material that has the ability to continually adapt to changes in its physiological or mechanical environment. The capacity of bone to resist mechanical forces and fractures depends not only on the quantity of bone tissue but also on its quality. Bone is a composite material, made from a collagenous matrix and from minerals. The collagenous matrix provides toughness (fracture resistance) and the minerals increase the bone’s stiffness (bending resistance). By itself, the mineral phase is brittle and fractures easily....