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.