Young Pigeon Disease Syndrome
The Young Pigeon Disease Syndrome (YPDS, Syn. " Young Bird Sickness " Circovirose ) is a viral infectious disease in pigeons , especially in the old 4 to 12 weeks young birds occurs. It is characterized by damage to the immune system that leads to secondary infections. Clinically it manifests itself primarily in diarrhea with dehydration . A causal treatment is not possible, only the accompanying diseases can be treated.
Pathogen and disease development
The pathogen of the YPDS is the pigeon circovirus (PiCV or CoCV) from the family of Circoviridae . However, stress factors (young pigeon flights in humid weather) or other viral infections ( paramyxovirus ) are obviously required for the disease ( factor disease ). The majority of the pigeons are only latently infected, disease outbreaks only occur in around 20% of the infected animals.
The virus causes damage to the lymph follicles in the spleen and bursa fabricii . In contrast to Psittacine Beak and Feather Disease - the circovirus infection of parrots - the bone marrow is not affected, so the number of white blood cells is mostly unchanged.
Secondary infections are decisive for the pathogenesis of YPDS . Escherichia coli is primarily involved. This bacterium is also present in the intestines of healthy pigeons and, due to the virus infection, multiplies very strongly and leads to the destruction of the intestinal flora ( dysbacteria ). E. coli causes intestinal inflammation which leads to a loss of water and thus to the dehydration of the animals. Through the damaged intestinal wall, further pathogens can now overcome the mucous membrane barrier and infections by protozoa (especially Spironucleus (Hexamita) columbae , pathogens of hexamitiasis ) or fungi ( aspergillosis ) develop .
It affects animals between 2 and 24 weeks of age; it occurs most frequently in 4 to 12-week-old young birds. The mortality varies between 20 and 50%.
Clinical picture
Young Pigeon Disease Syndrome is a general infection with few specific symptoms. The infection occurs through latent virus carriers via feather dust, feces and direct contact. In a herd, the disease usually spreads within a few days, sometimes over weeks.
In addition to fatigue, reluctance to eat and reluctance to fly, there are insatiable slimy diarrhea with dehydration as well as green-watery fluid accumulation due to biliary backlog in the goiter ("water goit"), stomach and intestines.
diagnosis
Clinically, the disease can only be made as a suspected diagnosis. In addition to a thorough anamnesis and examination of faecal samples for accompanying pathogens, virus detection must be carried out from organ samples, blood or throat or cloacal swabs using the polymerase chain reaction . Since this only detects virus DNA, but the pathogen also occurs in non-diseased birds, the virus detection is not yet a reliable diagnostic criterion.
Pathohistologically , necrosis and cell depletion of the lymph follicles are evident. Inclusion bodies appear in the cytoplasm of the macrophages in around half of the infected animals , but these can also be detected in non-diseased animals.
The differential diagnosis especially the need adenovirosis ( "Moss disease") and a coccidiosis be excluded.
Combat
There is no effective antiviral therapy . The prophylaxis therefore has a crucial importance. Above all, it aims to consistently avoid stress (stocking density, avoiding flights on hot days, careful training), adequate vitamin intake , separation of old and young birds, daily changing of the drinkers and regular cleaning and disinfection measures.
In the event of an outbreak, the secondary infections can be treated with antibiotics, whereby an antibiogram is strongly recommended.
literature
- Norbert Kummerfeld: Circovirus . In: K. Gabrisch, P. Zwart: Diseases of pets. 6th ed., Schlütersche Verlagsgesellschaft, Hannover 2005, p. 575. ISBN 3-89993-010-X
- Volker Schmidt: Young pigeon disease of the carrier pigeon - Recent research results on the etiology. kleintier specifically 4/2007, pp. 26–30.
