Lesions and viral loads in racing pigeons naturally coinfected with pigeon circovirus and columbid alphaherpesvirus 1 in Australia. (May 2023)

• Record Type: Journal Article
• Authors: Nath, Babu K.; Das, Shubhagata; Tidd, Naomie; Das, Tridip; Forwood, Jade K.; Raidal, Shane R.
• Is Part Of: Journal of veterinary diagnostic investigation. Volume 35:Number 3(2023)
• Page Start: 278
• Page End: 283
• Publication Date: 2023-05
• Subjects: Columba livia -- coinfection -- columbid herpesvirus 1 -- pigeon circovirus -- pathology -- qPCR; Veterinary medicine -- Diagnosis -- Periodicals; 636.0896075
• DOI: 10.1177/10406387231156839
• Languages: English
• ISSNs: 1040-6387

Abstract

Columbid alphaherpesvirus 1 (CoHV1) is associated with oral or upper respiratory tract lesions, encephalitis, and occasional fatal systemic disease in naive or immunosuppressed pigeons. Clinical disease is often reported with CoHV1 and coinfecting viruses, including pigeon circovirus (PiCV), which may cause host immunosuppression and augment lesion development. A natural outbreak of CoHV1 and PiCV coinfection occurred in a flock of 60 racing rock pigeons ( Columba livia ), in which 4 pigeons succumbed within 7 d of clinical onset. Lesions included suppurative stomatitis, pharyngitis, cloacitis, meningitis, and tympanitis, with eosinophilic intranuclear inclusion bodies consistent with herpesviral infection. In addition, large numbers of botryoid intracytoplasmic inclusion bodies were present in the skin, oral mucosa, and bursa of Fabricius, suggestive of circoviral infection, which was confirmed by immunohistochemistry. The concurrent viral load of CoHV1 and PiCV was high in liver, oropharynx, and bursa of Fabricius. We found PiCV in oro-cloacal swabs from 44 of 46 additional birds of variable clinical status, PiCV alone in 23 birds, and coinfection with CoHV1 in 21 birds. Viral copy numbers were significantly higher ( p < 0.0001) for both viruses in clinically affected pigeons than in subclinical qPCR-positive birds. The CoHV1-induced lesions might have been exacerbated by concomitant PiCV infection.