Marine Harvest denied earlier reports about salmon being attacked by a virus.
According to the BBC, large numbers of fish are being collected from a sea loch on the Isle of Lewis after suffering bacterial infection.
Steve Bracken, from Marine Harvest, said: “Our vet believes it is Pasteurella skyensis, although we are awaiting final confirmation from the laboratory results.”
He also added: “The salmon are responding well to treatment and we hope that we are close to resolving the problem.”