The pigeon circovirus evolution, epidemiology and interaction with the host immune system under One Loft Race rearing conditions.

This study was aimed to investigate the frequency of PiCV recombination, the kinetics of PiCV viremia and shedding and the correlation between viral replication and host immune response in young pigeons subclinically infected with various PiCV variants and kept under conditions mimicking the OLR system. Fifteen racing pigeons originating from five breeding facilities were housed together for six weeks. Blood and cloacal swab samples were collected from birds every seven days to recover complete PiCV genomes and determine PiCV genetic diversity and recombination dynamics, as well as to assess virus shedding rate, level of viremia, expression of selected genes and level of anti-PiCV antibodies. Three hundred and eighty-eight complete PiCV genomes were obtained and thirteen genotypes were distinguished. Twenty-five recombination events were detected. Recombinants emerged during the first three weeks of the experiment which was consistent with the peak level of viremia and viral shedding. A further decrease in viremia and shedding partially corresponded with IFN-γ and MX1 gene expression and antibody dynamics. Considering the role of OLR pigeon rearing system in spreading infectious agents and allowing their recombination, it would be reasonable to reflect on the relevance of pigeon racing from both an animal welfare and epidemiological perspective.

Occurrence and Phylogenetic Analysis of Avian Coronaviruses in Domestic Pigeons (Columba livia domestica) in Poland between 2016 and 2020.

While disease control in racing pigeons and the potential role of pigeons as vectors transmitting viruses to poultry are of importance, there is still a paucity of data concerning the occurrence of coronaviruses in pigeons. In this study, 215 domestic pigeons were tested for the presence of coronaviral genetic material using the nested PCR method, which revealed 57 positive samples (26.51%). The difference in coronavirus prevalence between young and adult pigeons (34.34% and 19.83%, respectively) has been found statistically significant. In contrast, no statistically significant difference has been demonstrated between the prevalence in symptomatic and asymptomatic birds, leaving the influence of coronavirus presence on pigeon health uncertain. Phylogenetic analysis of the RdRp gene fragment allowed us to assign all the obtained strains to the Gammacoronavirus genus and Igacovirus subgenus. The phylogenetic tree plotted using the ML method revealed that those sequences formed a group most similar to pigeon coronavirus strains from China, Finland, and Poland, and to a single strain from a common starling from Poland, which suggests wide geographical distribution of the virus and its possible transmission between various species.

Occurrence and Role of Selected RNA-Viruses as Potential Causative Agents of Watery Droppings in Pigeons.

The diseases with watery droppings (diarrhea and/or polyuria) can be considered some of the most severe health problems in domestic pigeons of various ages. Although they do not always lead to bird death, they can contribute to poor weight gains and hindered development of young pigeons and, potentially, to poor racing results in sports birds. The gastrointestinal tract disorders of pigeons may be of various etiology, but some of the causative agents are viral infections. This review article provides information collected from scientific reports on RNA-viruses belonging to the Astroviridae, Picornaviridae, and Coronaviridae families; the Avulavirinae subfamily; and the Rotavirus genus that might be implicated in such health problems. It presents a brief characterization, and possible interspecies transmission of these viruses. We believe that this review article will help clinical signs of infection, isolation methods, occurrence in pigeons and poultry, systemize and summarize knowledge on pigeon enteropathogenic viruses and raise awareness of the importance of disease control in pigeons.