Equine multinodular pulmonary fibrosis in three horses in Australia

Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease.

Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EHV-5 in hepatic tissue in one case. Two of the three horses died. Treatment with acyclovir was unsuccessful in one horse and one horse survived without antiviral or corticosteroid treatment.

This case series is, to the authors' knowledge, the first report of EMPF in Australia and adds to the clinical description of the disease.