Malignant catarrhal fever caused by ovine herpesvirus‐2 in a sanctuary‐housed mixed breed pig

Abstract An 11‐month‐old, male, crossbreed production barrow presented for recurrence of pyrexia 1 month after previous hospitalisation. During the initial visit, it was treated symptomatically with broad‐spectrum antimicrobials and anti‐inflammatories. Testing was performed for porcine circovirus, pseudorabies and porcine reproductive and respiratory syndrome virus, all of which were negative. Following a weeklong initial hospitalisation, it became afebrile and was discharged. Four weeks later, it re‐presented with recurring pyrexia. The barrow failed to respond to medical management, and euthanasia was elected with postmortem examination. Histological findings were consistent with widespread vasculitis. Frozen brain was submitted to an external laboratory for ovine herpesvirus‐2 PCR, which was positive (Ct = 25.4). Nasal swabs from the four sheep that were housed with the pig were also submitted for ovine herpesvirus‐2 PCR, and one sheep was positive for ovine herpesvirus‐2 (Ct = 32.7). This case represents cross‐species transmission of ovine herpesvirus‐2 from sheep to a co‐habitated pig.