Congenital suipoxvirus infection in newborn piglets in an Austrian piglet producing farm

Abstract Background The purpose of this case is to describe the occurrence of congenital swinepox virus infection in new born piglets of a single litter in a conventional piglet producing farm in Austria. In February 2020, a fourth parity sow gave birth to a litter of piglets with four piglets presenting pox-like skin lesions. Lesions were distributed over the whole skin surface and ulcerative lesions were also observed on the mucosa of the oral cavity. The herd attending veterinarian included the University Clinic for Swine to identify the cause of observed skin lesions, since such skin lesions had never been observed before. Case presentation The skin lesions were described to look like pox-lesions. A sow of fourth parity gave birth to one stillborn and 16 live-born piglets. In total, four out of 16 piglets had pox-like lesions distributed over the whole body and on oral mucosa. One affected piglet died on the fourth day of life and two were euthanized due to starvation and animal welfare reasons. Three affected piglets were sent to the University Clinic for Swine for further diagnostics. The sow and the remaining littermates did not show any skin lesions. Virological and histopathological investigations confirmed congenital suipox virus infection. Since there is no effective treatment available, the farmer was recommended to improve hygiene. No further cases occurred after this single event. Conclusion Nowadays, infections with suipox virus are rarely reported in conventional pig production as the disease is usually self-limiting in older pigs and is perceived with low economic impact. In the past, suipox virus infections were mainly related to improper hygiene conditions and pig lice as vectors. Today conventional pigs are usually kept under good hygienic conditions and pig lice are not reported anymore to occur in Austrian conventional pig farming systems. Therefore, we speculate, that other living vectors, such as the stable fly may play a role in transmission of suipox virus between and within farms and in the occurrence of congenital suipox virus infections in neonatal piglets.