Introduction
Viral infections of pigeons, particularly under the age of 1, are associated with high morbidity and mortality. It has been reported that Pigeon aviadenovirus A (Duchatel et al., 2000; De Herdt et al., 1995) and Pigeon circovirus (Todd, 2000) are associated with an immuno supression syndrome called “Young Pigeon Disease Syndrome” (YPDS).
Pigeon aviadenovirus A (PiAdV-A) is a member of the genus Aviadenovirus with in the family Adenoviridae(Raue et al., 2002). To date, the Aviadenovirus genus is made up of 14 different members incluiding, Duck aviadenovirus B, Falcon aviadenovirus A, Fowl aviadenovirus A-E, Goose aviadenovirus A, Pigeon aviadenovirus A-B, Psittacine aviadenovirus B and Turkey aviadenovirus B-D.
Pigeon circovirus (PiCV) is a member of the Circovirus genus, family Circoviridae (Mankertz et al., 2000) and within this family there are 10 viruses that infect and cause disease in birds; incluiding, Pigeon circovirus, Beak and feather disease virus, Canary circovirus, Goose circovirus, Duck circovirus, Gull circovirus, Raven circovirus, Swan circovirus, Chicken associated cyclovirus 1 and Duck associated cyclovirus 1.
Pigeons with adenovirus infection were originally reported by McFerran et al. in 1976 (McFerran et al., 1976a), although PiAdV infection was firstly isolated and identified in 1984 in Belgium. Pigeons infected with PiAdV have since been observed all around the world (Vereecken et al., 1998). Although pigeons of any age can be infected, young pigeons under one year of age are particularly badly affected by PiAdV-A, showing acute watery diarrhoea, vomiting and anorexia. PiAdV-B affects pigeons of all ages and is characterized by sudden death and intensive hepatic necrosis (Duchatel et al., 2000; De Herdt et al., 1995; Vereecken et al., 1998). The annual pigeon mortality rate is very high, with approximately 30% due to PiAdV, but in some cases it can reach 100% in pigeon lofts with necrotizing hepatitis infections (Vereecken et al., 1998).
PiCV was first diagnosed in Canada in 1986, although it is known to be present across the World (Hess et al., 1998, Woods et al., 1993) and, similar to PiAdV-A, it is younger pigeons that are mainly affected by it (2 months - 1 year of age) (Pare et al., 1999; Takase et al., 1990; Tavernier et al., 2000; Todd, 2000; Woods et al., 1994). PiCV infection can induce a wide spectrum of non-specific clinical signs including lethargy, weight loss, respiratory distress and diarrhoea (Woods et al., 1994). Until recently, it was unclear what effect many aviadenoviruses had on animals, but now the impact of viruses such as the Fowl aviadenoviruses (FAdV) is well recognised (Hess, 2013). These FAdV strains can cause gizzard erosion (GE), hydropericardium syndrome (HS) and severe liver damage leading to the condition known as inclusion body hepatitis (IBH) and serotypes 2, 4, 5, 6, 8, 10 and 12 have been isolated from both diseased and healthy pigeons (Goryo et al., 1988; Hess et al., 1998a; Hess et al., 1998b; McFerran et al., 1976a). In this study we report the isolation and analysis of both PiAdV and PiCV from a co-infection in pigeons in central Anatolia, Turkey.