In summary, Borna Disease Virus (BDV) is a rare but potentially deadly virus that primarily affects animals, particularly horses and sheep. While there have been cases of BDV infecting humans, it is not known to cause illness or disease in humans. However, research suggests that exposure to BDV may have a link to certain mental disorders, such as bipolar disorder and schizophrenia. Further studies are needed to fully understand the potential effects of BDV on human health.