Dr. Rob Marshall, B. V. Sc, M.A.V. C. Sc (Avian Health)
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Video of LOT 1 “Good As Gold” being sold to an anonymous telephone bidder at the auction yesterday in Adelaide, South Australia
Video Source: Willie Theille
Valerij Akimkin (CVUAS), Andreas Hänel (CVUAS), Alexandra Kley-Sonntag (STUA AU-DZ), Anja Spadinger (STUAAU-DZ), Ernst Großmann (STUAAU-DZ)
Source: http://www.cvuas.de/pub/beitrag.asp?subid=1&Thema_ID=8&ID=2632&Pdf=No&lang=DE
Rotaviruses are associated with treacherous diarrhea, which can be particularly severe in infants and toddlers. If the little patients are not treated in time, a rotavirus infection can also be fatal. But not only in humans, these diarrhea pathogens occur. Rotaviruses have been detected in many species of mammals and birds. The main symptom of this infection is always the same: diarrhea. At the CVUA Stuttgart and at the STUA Aulendorf – Diagnostic Center, rotavirus tests are routinely performed on calves, piglets, and chicks with gastrointestinal disturbances. In hundreds of samples, we have already found the virus. Recently, the virological laboratory of the CVUA Stuttgart could detect rotaviruses in pigeons. Until recently, rotavirus infection was largely unknown in these birds. Only since 2016, more rotavirus diarrhea in letter and breed pigeons on the Australian continent. In this paper, we report on three rotavirus infection outbreaks in wild and kept pigeons in Baden-Württemberg.
At the beginning of November 2017, there was an outbreak of infection in breeding pigeons in the district of Esslingen. In a stock with about 50 pigeons of the breeds at the Rheinische Ringschläger and Thurgauer Elmer occurred within a few days several deaths. The pigeons were housed in 3 aviaries with sand bottom, which were covered to one third. As the first animal, a young female was puffed up and died within 24 hours. A young robber who had previously been kept in a domestic attack also died after spending a few days in the robbery after the onset of weakness. A third youngster died a few days later without any recognizable signs of illness. The dead animals came from two different aviaries. The third aviary was not affected.
The feed used was a commercial pigeon feed with added wheat. The last new entry was made in early 2017. Participation in exhibitions had not taken place.
Two of the dead birds, a young female, and a youngster, were sent to the State Veterinary Investigation Office Aulendorf – Diagnostikzentrum (STUA Aulendorf-DZ) to determine the cause of death. Both pigeons were in a moderate nutritional status and had a high degree of spleen swelling and catarrhal bowel inflammation. Craw and stomach were food-free.
The liver had profuse, diffuse, acute degeneration and necrosis, as well as a high-grade, multifocal, periportal-accentuated monocytic inflammation (Figure 1). Furthermore, a marked degree of hemosiderosis of the liver was noticeable. Both animals had low-grade, multifocal, interstitial monocytic nephritis.
1: Histological picture of the liver. Shown is a hematoxylin-eosin staining at 20x magnification. High-grade, diffuse, acute degeneration and necrosis can be seen, as well as a high-grade, multifocal, periportal accentuated monocytic inflammation. Also striking is the high-grade hemosiderosis.
Bacteriological examination of the liver revealed only nonspecific germ growth. From the intestine, a physiological intestinal flora could be detected. By means of enrichment procedures, no Salmonella was isolable. Endoparasites were undetectable in both young pigeons. However, both animals had a high infestation with featherlings. An infection with Paramyxovirus 1 could be excluded by molecular biological examination.
Electron microscopic examination of liver and spleen samples at the CVUA Stuttgart clearly identified rotaviruses in large numbers (Figure 2). In this case, it is assumed that rotaviruses were the cause of disease and death of the pigeons.
Figure 2: Rotavirus particles in the liver sample of a diseased pigeon. Electron micrograph, magnification 250,000 times.
At about the same time, another outbreak of infection occurred. In Backnang in the Rems-Murr-Kreis in a narrow circle, 5 street pigeons were found dead. One of the pigeons was forwarded to the CVUA Stuttgart by the competent veterinary office to determine the cause of death. In particular, it was to be clarified whether the pigeons had been shot down or poisoned.
The carcass submitted for examination was – as can be seen from the lentil-sized Bursa cloacalis – a young pigeon in poor nutritional status. Craw and stomach were food-free, in the gizzard only Gritsteinchen available. The main findings were high-grade catarrhal bowel inflammation and hepatic congestion. Evidence of the effects of trauma was not found. Also, poisoning seemed unlikely due to the lack of bait material in the crop and stomach of the animal.
The bacteriological organ findings were inconspicuous. A parasitological examination was able to exclude infestation with both intestinal parasites and trichomonads. A real-time PCR, which was used to examine a pigeon brain sample for Paramyxovirus 1 infection, also revealed a negative result.
Figure 3: Street pigeons in the city can also develop rotavirus infection. Figure
Inspired by a report in a pigeon fancier journal that a novel highly pathogenic rotavirus has been spreading in letter and breeding pigeon flocks in Australia for about one year, an initially frozen liver sample of the pigeon was examined by electron microscopy.
In the electron microscopic examination of liver samples at the CVUA Stuttgart, large numbers of rotaviruses were clearly identified, as in the first described case in racial pigeons (Figure 4). Also, in this case, it is assumed that rotaviruses were the cause of death of the pigeons.
Because of this diagnosis, a dying already a month ago in Althütte, also Rems-Murr-Kreis, again under the magnifying glass. On a company site, several dead street pigeons were found within a few days. An initially suspected poisoning could be ruled out. Also, in this case, numerous rotavirus particles were found in the subsequent electron microscopic examination of an asserted liver sample and thus the diagnosis of a rotavirus infection was made.
Figure 4: Numerous rotaviruses in the liver sample of a pigeon. Electron micrograph, magnification 120,000 times.
The described cases show that rotavirus infections in Baden-Württemberg can lead to an acute illness with death in both wild and caged pigeons. Due to the small number of proven cases, a statement about the spread of the infection in Baden-Württemberg is not yet possible.
The virological institute of the University Hospital Freiburg was able to prove the genome of group A rotaviruses in further investigations of organ samples from both outbreaks of infection.
A molecular biology typing of the virus was initiated. This is to clarify how close the Rotaviruses from Australia and Baden-Württemberg are related to each other.
Information
rotavirus
Rotaviruses are members of the Reoviridae virus family. The pathogen is considered to be the leading cause of diarrhea in humans as well as mammals and birds. The disease occurs mainly in infants or young animals.
In the electron microscope, rotaviruses can be represented as round, about 70 nm to 80 nm large uncoated particles. The virus genome consists of 11 segments of double-stranded RNA. Rotaviruses are divided into 8 groups (A to H) and several subgroups (see P [] and G [] genotypes).
The transmission of the infection is fecal-oral. It is a typical smear infection. In acute cases, large amounts of virus are excreted in the feces (10 9 -10 11 virus particles in 1 g feces). The viruses show high resistance to environmental influences and can remain infectious in feces for several weeks.
The incubation period is usually very short. Already 24 hours after the infection first symptoms appear like watery diarrhea, lack of appetite and restlessness.
The virus is detected directly in the feces or intestinal contents by electron microscopy or by the polymerase chain reaction (PCR). For some species, ELISA tests are also available to detect the virus antigen.
Therapeutic measures are not very effective. Prophylactic vaccination is possible in some species.
Rotavirus was first detected in pigeons in 1988, but until recently they were not associated with a serious disease of these birds. Accordingly, there is little information in the literature about the distribution of these viruses in pigeons. Since May 2016, more and more outbreaks of pigeon populations have been recorded in Australia. The animals show the typical symptoms of rotavirus infection, such as diarrhea, apathy, and loss of appetite. The World Organization for Animal Health (OIE) currently estimates morbidity (incidence rate) at 50% and mortality (mortality rate) at 20%. The rotavirus strain isolated from the pigeons is considered harmless to humans.
photo Credits
Figure 1: Ernst Grossmann STUA Aulendorf – Diagnostic Center
Figures 2-4: Valerij Akimkin CVUA Stuttgart
sources
[1] Rubbenstroth D., Teske L., Rotaviruses – a threat to pigeon populations in Europe ?, The carrier pigeon 134 (2017) No. 27