Tick-borne encephalitis virus associated with foetal death in a bitch, a case report

BackgroundFor the first time, a case of vertical transmission of TBEV in a dog associated with foetal death is described.Case presentationA six-year-old beagle bitch experienced foetal death from day 49 in pregnancy. A caesarean section was performed on day 56, and one live and three dead pups in different stages of resorption were delivered. Black mucoid, non-smelling foetal membranes surrounded the dead foetuses. The live-born foetus died despite efforts to save it and was sent for autopsy together with the placenta. Autopsy demonstrated lung atelectasis and no malformations. A mild acute necrotizing placentitis was diagnosed on histopathology. Selective bacteriological cultures for Brucella canis from blood, vagina and the foetus were all negative, as was PCR for canine herpes virus (CHV). Viral metagenomics analysis identified the presence of tick-borne encephalitis virus (TBEV) in the placental tissue and in situ hybridization revealed TBEV in the trophoblasts. The bitch had antibodies to TBEV. One year later, the bitch had a normal pregnancy and whelping.ConclusionWith the spread of both ticks and TBEV, infection with TBEV should be given further consideration as a potential differential diagnosis in cases of foetal death in dogs.