Gill diseases cause serious losses in farming of Atlantic salmon and the number of agents involved increases. Salmon gill poxvirus ( SGPV ) and the gill disease in causes where SGPV apparently was the only disease‐causing agent were initially characterized. Recently, it was further shown that SGPV can be a common denominator in widely different multifactorial gill diseases. Here, we present the challenge of diagnosing gill dis...

Gill diseases cause considerable losses in Norwegian salmon farming. In 2015, we characterized salmon gill poxvirus ( SGPV ) and associated gill disease. Using newly developed diagnostic tools, we show here that SGPV infection is more widely distributed than previously assumed. We present seven cases of complex gill disease in Atlantic salmon farmed in seawater and freshwater from different parts of Norway. Apoptosis, the hall...

Serious infectious diseases, accompanied by macrophage‐dominated chronic inflammation, are common in farmed Atlantic cod. To increase knowledge relating to morphological aspects of such inflammatory responses, cod were challenged with Francisella noatunensis , an important bacterial pathogen of this fish species. Tissue and cell dynamics in the spleen were examined sequentially over 60 days. Small clusters of mainly macrophage...