Detection of retrovirus sequences in budgerigars with tumours

Abstract

Renal tumours are a common neoplastic disease of budgerigars. Although a retro-virus has been implicated as the aetiological agent, there is no definitive proof for this hypothesis. Sixteen birds suspected to have renal tumours were examined in an attempt to elucidate the possible role of retroviruses. Thirteen birds had renal tumours and the majority of these birds showed abdominal enlargement and paresis. Renal masses were detected by radiography in nine birds. Post-mortem examination confirmed the presence of abdominal tumours which were mostly confined to the kidneys. All of the renal tumours were carcinomas. ELISA tests to detect the presence of p27 of avian leukosis virus and virus isolation attempts were negative. DNA from eight tumours was examined by dot-blot hybridization for the presence of sequences hybridizing with a full length clone of the RAV-2 strain of the avian leukosis virus. A positive reaction was detected with DNA from 6/8 tumours. Southern blot hybridization demonstrated the presence of a 7.2 kb fragment following restriction with BamHI and a 4.6 kb fragment in an additional tumour following digestion with EcoRI that were recognized by the RAV-2 probe. These results suggest the presence of a retrovirus in tumours of budgerigars.

Investigations on the diagnosis and retroviral aetiology of renal neoplasia in budgerigars (Melopsittacus undulatus)

“…Fresh tissue samples from kidneys or kidney neoplasia obtained from four birds were collected in PBS (pH 7.2) and sent to the veterinary laboratory, Vetsuisse Faculty, University of Zurich for primary cell cultures. Samples were prepared in a medium as described by Gould et al (1993). The culture medium was exchanged on days 5, 11, and 19, and supernatants were subsequently submitted for PERT assay.…”

“…It was speculated that the difference between the results of these two studies was due to the different ELISA tests used. Dot-blot hybridization of DNA extracted from renal neoplasms reacted positive in six of eight renal neoplasia samples (Gould et al, 1993). All eight specimens were further analysed by Southern blot hybridization.…”

“…Although direct evidence for the presence of ALV gs antigen was obtained in 47% of the birds, the presence of this antigen was not specific for kidney neoplasia, as it was also found in budgerigars that did not suffer from this disease. An alternative approach was used by Gould et al (1993). These authors tested for the hypothesized presence of ALV by applying an ELISA for viral antigen and by dot-blot hybridization for the presence of retroviral RNA sequences with a probe derived from Rous-associated virus-2 (RAV-2).…”

Field isolates of fowlpox virus contaminated with reticuloendotheliosis virus

“…Various techniques, including ELISA (Cui et al, 1988), the complement fixation test (CFT) , immunofluorescent assays (IFA) (Bagust & Dennet, 1977) and hybridization techniques (Gould et al, 1993) have been used for the detection of REV in tumorigenic tissues, blood and plasma. Aly et al (1993) devised a PCR using sequences of the long terminal repeats (LTR) of the SNV, a member of the REV group, to detect REV in blood.…”

Metastatic cholangiocellular carcinoma and renal adenocarcinoma in a golden eagle(Aquila chrysaetos)

“…Ipsilateral paresis, secondary to compression of the ischiatic nerve, is the most common clinical sign associated with renal neoplasia in birds (Gould et al, 1993). In the case reported here, the main tumour was small (11 mm) and pressure on the sciatic nerve was not observed.…”