A disease complex associated with pigeon circovirus infection, young pigeon disease syndrome

Abstract

In order to collect more convincing data on the aetiological agent of young pigeon disease syndrome (YPDS), a comprehensive study was performed on pigeons in German lofts with or without outbreaks of YPDS. The investigations included examination of histories, clinical signs and pathology, as well as parasitological and microbiological analysis. Pigeons in their 4th to 12th week of life exhibited clinical signs at higher frequency and with greater severity than pigeons of other ages. Greenish liquid in the crop, proventriculus and ventriculus, and yellow fluid in the small intestine were seen more often in YPDS-affected pigeons. Escherichia coli and Klebsiella pneumoniae were isolated more frequently from these birds. Depletion of splenic and bursal lymphocytes was only seen in pigeons with YPDS. Inclusion bodies were present in various organs, especially the bursa of Fabricius. The genome of pigeon circovirus was detected in lymphoid tissues from all pigeons with YPDS. The results of this study indicate that YPDS is a multifactorial disease in which pigeon circovirus might be a crucial factor, possibly by inducing immunosuppression in infected birds.

Occurrence and genetic diversity of pigeon circovirus strains in Poland

“…Based on previous studies the authors of this publication agree with certain hypotheses, which argue that changes in capsid protein structure may have an influence on the formation of resistance against this virus (Cságola et al, 2012). Pigeon circovirus infections do not cause large losses directly associated with the infection as observed in the case of paramyxoviruses (Aldous et al, 2004), although it is noteworthy that they are very strong immunosuppressants favouring the occurrence of associated infections which can in turn cause huge losses in flocks (Todd, 2000;Raue et al, 2005;Stenzel et al, 2012). Veterinaria Hungarica 62, 2014 Taking into consideration the fact that PiCV infections are very common, development of a vaccine appears necessary.…”

“…Pigeon circovirus infections are very common all around the world (Smyth and Carroll, 1995;Paré et al, 1999;Caletti et al, 2000;Raue et al, 2005;Freick et al, 2008;Zhang et al, 2011;Cságola et al, 2012;Stenzel et al, 2012). The results obtained in this study indicate the high prevalence of PiCV infections in Poland.…”

“…In addition, histopathological examination of the organs taken from sick birds has shown the presence of characteristic intracytoplasmic botryoid inclusion bodies in the cells of the lymphatic tissue (Caletti et al, 2000). A weakened immune response in infected pigeons predisposes the birds to opportunistic infections and superinfections by other viruses such as pigeon herpesvirus (PiHV) and pigeon adenovirus (PiAV) (Raue et al, 2005;Stenzel et al, 2012). Pigeon circovirus has been isolated from both healthy and symptomatic birds of all ages, which form the basis for the hypotheses that additional factors are needed for the development of YPDS, or that there are PiCV strains of different virulence (Schmidt et al, 2008;Zhang et al, 2011;Cságola et al, 2012;Stenzel et al, 2012).…”

“…Pigeon circovirus infections are very common in the domestic pigeon population, and their clinical form occurring in young birds is called Young Pigeon Disease Syndrome (YPDS) (Smyth and Carroll, 1995;Paré et al, 1999;Raue et al, 2005;Duchatel et al, 2005Duchatel et al, , 2006Zhang et al, 2011;Cságola et al, 2012;Stenzel et al, 2012). Circoviral infection in pigeons can be manifested in a wide range of signs including weight loss, decrease in racing performance, respiratory problems, diarrhoea, and occasional problems with plumage development (Raue et al, 2005).…”

“…Circoviral infection in pigeons can be manifested in a wide range of signs including weight loss, decrease in racing performance, respiratory problems, diarrhoea, and occasional problems with plumage development (Raue et al, 2005). Pigeon circovirus infection leads to a loss in lymphoid tissue layer and lymphocyte apoptosis, which is the main cause of immunosuppression in the infected birds (Todd, 2000;Abadie et al, 2001;Raue et al, 2005). In addition, histopathological examination of the organs taken from sick birds has shown the presence of characteristic intracytoplasmic botryoid inclusion bodies in the cells of the lymphatic tissue (Caletti et al, 2000).…”