Investigation of Three Newly Identified Equine Parvoviruses in Blood and Nasal Fluid Samples of Clinically Healthy Horses and Horses with Acute Onset of Respiratory Disease.
Authors: Pusterla Nicola, James Kaitlyn, Barnum Samantha, Delwart Eric
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers at UC Davis investigated whether three newly discovered equine parvoviruses—equine parvovirus hepatitis (EqPV-H), equine parvovirus CSF (EqPV-CSF) and equine copivirus (Eqcopivirus)—play a role in equine respiratory disease, as initial reports had suggested a possible link. Using qPCR analysis of nasal fluid and blood samples from 667 horses presenting with acute fever and respiratory signs, plus 87 clinically healthy controls, they tested for these parvoviruses alongside established respiratory pathogens (equine influenza, herpesviruses 1 and 4, rhinitis viruses and *Streptococcus equi*). Whilst 117 sick horses tested positive for at least one parvovirus and 39 showed co-infections with conventional pathogens, the detection rate of these parvoviruses in respiratory disease cases was not significantly different from the 10 healthy horses that also tested positive (p > 0.05), suggesting these viruses are likely incidental findings rather than primary drivers of clinical respiratory disease. For practitioners managing equine respiratory infections, this finding implies that positive qPCR results for these three parvoviruses should not redirect diagnostic attention away from conventional pathogens, and that isolation or treatment decisions should continue to focus on established aetiologies with proven clinical significance.
Read the full abstract on PubMed
Practical Takeaways
- •The three newly identified equine parvoviruses appear to be incidental findings in horses with respiratory disease and should not be presumed as primary causative agents when detected
- •Diagnostic testing for EqPV-H, EqPV-CSF, and Eqcopivirus has limited clinical utility for managing acute respiratory disease in horses, as their presence does not correlate with clinical signs
- •Continue to focus diagnostic and therapeutic efforts on established equine respiratory pathogens (influenza, herpesvirus, rhinitis, S. equi) rather than these newly discovered parvoviruses
Key Findings
- •117 of 667 sick horses (17.5%) tested positive for at least one of three newly identified equine parvoviruses
- •39 sick equids had co-infections with common respiratory pathogens and parvoviruses
- •10 of 87 clinically healthy control horses (11.5%) tested positive for equine parvoviruses
- •No statistically significant difference in parvovirus detection between sick and healthy horses (p > 0.05), suggesting these viruses do not contribute to clinical respiratory disease