Funding for this research was provided by:
Dansk Pelsdyravlerforenings Forskningsfond
Received: 8 January 2021
Accepted: 26 March 2021
First Online: 1 April 2021
: No ethical or laboratory animal permission was required as only spontaneous disease outbreaks were studied and as no experimental infection of animals took place. The animals were handled according to national legislation.
: Not applicable.
: The authors declare that they have no competing interests.