Identification of asinine gamma herpesviruses in a donkey with interstitial pulmonary fibrosis, pleural effusion and thrombocytopenia.
Authors: Imposimato Ilaria, Muscatello Luisa Vera, Ellero Nicola, Lelli Davide, Mira Francesco, Sarli Giuseppe, Freccero Francesca
Journal: Journal of equine veterinary science
Summary
A 23-year-old donkey presenting with acute respiratory distress revealed bilateral pulmonary consolidation and pleural effusion on ultrasound examination, initially suggestive of equine asthma, though post-mortem investigation uncovered a far more complex pathology. Despite intensive treatment including identification of *Streptococcus equi* subsp. *zooepidemicus* via tracheal wash culture and endoscopic evidence of severe neutrophilic airway inflammation, the animal deteriorated rapidly and died within 48 hours. Histopathological examination and molecular analysis identified asinine gammaherpesvirus types 2 and 5 as the underlying drivers of marked interstitial pulmonary fibrosis with pleuritis, distinguished from the nodular pattern typically seen in equine multinodular pulmonary fibrosis by its diffuse interstitial distribution and type 2 pneumocyte hyperplasia. Whilst herpesviral pulmonary fibrosis remains uncommon in donkey populations, this case demonstrates that asinine gammaherpesviruses warrant inclusion in the differential diagnosis framework for donkeys presenting with chronic or progressive respiratory compromise, particularly where standard antimicrobial and anti-inflammatory protocols fail to resolve clinical signs. Clinicians should consider polymerase chain reaction testing of respiratory samples in such cases, as identifying herpesviral involvement may alter prognostic assessment and guide management decisions in what remains a potentially rapidly fatal condition.
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Practical Takeaways
- •Consider asinine gammaherpesvirus infection in the differential diagnosis for donkeys presenting with chronic respiratory signs and progressive respiratory distress, not just equine asthma.
- •Be aware that herpesviral pulmonary fibrosis in donkeys may present similarly to other respiratory conditions but follows a different fibrotic pattern than equine multinodular pulmonary fibrosis.
- •Recognize that secondary bacterial infections (such as Streptococcus equi zooepidemicus) may complicate herpesviral respiratory disease, but aggressive antimicrobial treatment alone may not prevent fatal outcomes if underlying viral infection is present.
Key Findings
- •A 23-year-old donkey presented with bilateral pulmonary consolidation and pleural effusion, ultimately showing diffuse interstitial pulmonary fibrosis on post-mortem examination.
- •Asinine gammaherpesvirus 2 and 5 were identified via PCR and sequence analysis in lung tissue with fibrosing interstitial pleuropneumonia and type 2 pneumocyte hyperplasia.
- •The fibrotic pattern in this donkey was diffuse and interstitial rather than the nodular distribution typical of equine multinodular pulmonary fibrosis.
- •Despite aggressive treatment for suspected equine asthma and confirmed secondary Streptococcus equi zooepidemicus infection, the donkey died within 48 hours of presentation.