A novel ephemeral fever rhabdovirus and a CHeRI orbivirus of a previously unidentified genetic lineage were isolated in mosquito cell line C6/36 cells as co-infecting agents from the spleen tissue of a dead farmed white-tailed deer (WTD; Odocoileus virginianus) in Florida. We designated the ephemeral fever rhabdovirus as Hardee County ephemerovirus 1, strain CHeRI ephemerovirus 1. The genetic sequences of the CHeRI orbivirus isolated in this work differ significantly from those of three previously described CHeRI orbivirus lineages. We designated this new virus as CHeRI orbivirus 4, strain CHeRI orbivirus 4-1. Whereas it remains unknown whether one, both, or none of the viruses contributed to the pathology, gross observations revealed that the dead WTD had severely congested and hemorrhagic lungs, and that its heart, kidneys, and spleen were also congested.

We report the isolation and coding complete genome sequences of a new CHeRI orbivirus from the spleen of a dead farmed white-tailed deer in Florida whose death was attributed to an infection by mule deerpox virus. Phylogenetic and genetic analyses support this new virus as the fifth strain of the CHeRI orbivirus 3 species, and we designated it CHeRI orbivirus 3–5. While our previous detections and isolations of CHeRI orbiviruses were from deer spleens that also contained epizootic hemorrhagic disease virus-2, or in one case, Hardee County ephemerovirus 1, no deerpox virus was isolated from the spleen of the animal in this report, marking the first time we have isolated a CHeRI orbivirus without a co-infecting agent.

Bovine viral diarrhea virus (BVDV) is a globally significant pathogen affecting both domestic livestock and wildlife, including white-tailed deer (WTD; Odocoileus virginianus). While experimental infections have demonstrated WTD susceptibility to BVDV, natural infections and associated reproductive outcomes remain scarcely documented. Here, we report the first confirmed case of naturally occurring BVDV-1 infection associated with fetal mummification in farmed WTD in Florida. A two-year-old doe experienced a stillbirth involving two mummified fetuses, which were submitted for necropsy and laboratory diagnostics. Gross findings included diarrhea and underdeveloped eyes in the fetuses, along with small white nodules indicative of amnion nodosum. While not harmful, this condition suggests underlying fetal compromise or intrauterine stress. Virus isolation using Vero E6 and bovine turbinate cell lines, along with a reverse transcription PCR (RT-PCR) assay specifically developed in this study, confirmed the presence of BVDV-1 (Pestivirus bovis) RNA in both maternal and fetal samples, suggesting vertical transmission. Sanger sequencing of RT-PCR amplicons further verified the virus species as BVDV-1. Differential diagnostics for other pathogens, including bluetongue virus, epizootic hemorrhagic disease virus, Mycobacterium spp., and Toxoplasma gondii, were negative. These findings underscore the importance of using biosecurity measures and including BVDV in the differential diagnosis of abortions to reduce the risk of BVDV transmission and potential outbreaks on deer farms, particularly those close to cattle operations. The molecular tools developed in this study provide a robust framework for improved detection and monitoring of BVDV in both wildlife and livestock populations.