Equine Multinodular Pulmonary Fibrosis Associated with Equine Herpesvirus 5 in a Horse in Brazil

Panziera, WeldenGiaretta, Paula RGaliza, Glauco J. NLim, AilamBolin, Steven RBorges, Carlos HFighera, Rafael ABarros, Claudio S. L

This report describes the first diagnosed case of equine multinodular pulmonary fibrosis associated with equineherpesvirus 5 (EHV-5) in a horse in Brazil. A 7-year-old Thoroughbred mare from a stud farm in southern Brazil died aftera chronic respiratory disease characterized by tachypnea, respiratory distress, and cough accompanied by weight loss,anorexia, and intermittent fever. Hematological findings included mild neutrophilia, lymphopenia, andhyperfibrinogenemia. At necropsy the cadaver was extremely emaciated and the lungs did not collapse when the rib cagewas removed. Significant gross lesions were restricted to the lungs and consisted of numerous, firm, coalescing noduleswidely distributed throughout the organ. The nodules were 1-5 cm in diameter, pale tan-white, and sharply demarcated fromthe scant normal lung parenchyma. Microscopically, the nodules consisted of marked expansion of the interstitium by wellorganized,mature collagen and infiltration by lymphocytes, macrophages, neutrophils and occasional eosinophils. Cuboidalepithelial cells lined the alveoli in affected areas and their lumina were filled with a moderate to high number of neutrophilsand foamy macrophages, which occasionally displayed oval amphophilic intranuclear inclusion bodies. Nucleic acidsequence analyses of amplicons from polymerase chain reaction assays targeting the viral gBand gHgenes showed closesthomology with multiple corresponding sequences of the gB and gH genes of EHV 5 available in GenBank.(AU)

1. respiratory
2. EHV-5
3. herpesviruses
4. equine multinodular pulmonary fibrosis
5. pneumonia
6. horse