The affected animals all had the same symptoms, such as vomiting and diarrhoea containing blood.
A spokesperson for the food safety authority said it was a severe illness. However, it was not yet clear if the illness was contagious or if it related to a number of individual cases.
The Norwegian Veterinary Institute came across two types of bacteria when carrying out autopsies, which did not explain the cause of the illness. Currently there are no concerns that the disease will cross borders into other countries.
