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Biomedical subjects

S R Raidal

Publications and source records attributed to S R Raidal.

At least 19 recordsLinked to original sources
PubMed2006

Chronic shoulder osteoarthritis in a loggerhead turtle (Caretta caretta).

This report describes the lesions seen in an extremely weak and emaciated adult male loggerhead turtle (Caretta caretta) found stranded near Perth, Western Australia. Blood collected from a dorsal cervical sinus immediately prior to euthanasia demonstrated severe anaemia, markedly elevated plasma concentrations of creatinine kinase (2263 U/L), alkaline phosphatase (58 U/L), urea (18.1 mmol/L) and hypoglycaemia (glucose 0.7 mmol/L). Necropsy examination demonstrated a severe chronic osteoarthritis of the right shoulder joint with marked remodelling of the glenoid fossa, coracoid, scapula and humerus. There was marked synovial effusion and periarticular fibrosis. Cytological examination and culture of synovial fluid failed to demonstrate an infectious agent. Other findings were low numbers of trypanorhynch cysts present on the surface of the liver and numerous spirorchid eggs in the attached mesentery. Several large and small spirorchid flukes were present in the heart and there was a localised endarteritis in the left aortic arch associated with this infection. Numerous nematode eggs and at least three species of spirorchid eggs were seen microscopically in faeces collected from the terminal colon. The pathogenesis and significance of these lesions is discussed.

Alkaline Phosphatase↗
PubMed2006

Infection with Photobacterium damselae subspecies damselae and Vibrio harveyi in snapper, Pagrus auratus with bloat.

OBJECTIVE: To diagnose the cause of chronic, low mortality associated with bloat in tanks of snapper at an aquaculture facility. DESIGN: A clinical, pathological and microbiological investigation into the cause of a low number of ongoing mortalities associated with bloat in snapper at an aquaculture facility is outlined. Necropsy, histology, microbiology and a comparison of haematology and water analysis from affected and unaffected fish and holding tanks, respectively were conducted. RESULTS: Affected moribund fish were found in lateral or dorsal recumbency floating on the water surface within 24 hours of death. Photobacterium damselae subspecies damselae was isolated from intestinal contents and Vibrio harveyi from the blood of affected fish and both were isolated from culture water. Both V harveyi and P damselae subspecies damselae isolates were sensitive to tetracycline, ciprofloxacin and sulphamethoxazole plus trimethoprim. Environmental parameters such as pH and dissolved oxygen were similar in tanks of affected and unaffected fish. Affected fish had gas distended swimbladders, anaemia, and the intestines were diffusely distended with a clear, pale yellowish fluid. Livers were mottled tan and green in a zonal pattern. Histologically the intestines of fish from tanks suffering mortality had a moderate granulocytic enteritis with oedema and infiltrations with eosinophilic granule cells that were also present as an infiltrate in the gills. There were elevated numbers of melanomacrophage centres and haemosiderin deposits in the spleen, kidney and liver of affected fish. CONCLUSION: Vibrio harveyi and Photobacterium damselae subspecies damselae infection should be recognised as potential pathogens of snapper held in water of less than optimal quality.

Animals↗
PubMed2006

Surgical removal of an ovarian tumour in a koi carp (Cyprinus carpio).

Ultrasonography, radiography and exploratory coeliotomy were used to diagnose and treat a large intracoelomic neoplasm from a female koi carp (Cyprinus carpio) presented for abdominal enlargement of several months duration. Feed was withheld for 1 week immediately prior to surgery and the fish was sedated with isoeugenol (AQUI-S) at a dose rate of 10 mL/L to facilitate diagnostic imaging techniques. Surgical anaesthesia was induced by adding tricaine (MS-222) 50 mg/L to the water and an exploratory coeliotomy and tumour removal was performed. The fish was allowed to recover in fresh water at 18 degrees C and salt was added slowly to the water over a period of 1 hour to a concentration of 5 g/L This concentration was maintained in a recovery pond for 1 week postoperatively. Enrofloxacin was administered intramuscularly (10 mg/kg) immediately, 3 days and 1 week postoperatively. A diagnosis of undifferentiated ovarian carcinoma was made on the basis of the histological appearance of the neoplasm and immunohistochemical staining.

Animals↗
PubMed2006

Airsac cystadenocarcinomas in cockatoos.

The clinical signs, radiographic and pathological findings of four histologically similar neoplasms that occurred as unilateral tumours projecting from the left axilla in three galahs (Eolophus roseicapillus) and one sulphur-crested cockatoo (Cacatua galerita) are described. In each case, the main reason for clinical presentation was respiratory distress. All cases were eventually fatal due to airway obstruction with evidence of extensive neoplastic invasion of the lungs, major airways and or humerus in all cases. A diagnosis of airsac cystadenocarcinoma was made in each bird on the basis of gross and histological appearance. The neoplasms were composed of fluid or air-filled sacs of proliferative cuboidal to squamous epithelial cells that stained positively with cytokeratin and negatively with vimentin. This was supported by a thin fibrovascular network although at least some areas in all four birds resembled airsac tissue. In some cases areas of haemorrhage, erythrophagocytosis, haemosiderosis and nodules of haemosiderophage infiltration with acicular cholesterol clefts were present in some parts of the sectioned tissue.

Air Sacs↗
PubMed2004

Haematopoietic necrosis in a goldfish (Carassius auratus) associated with an agent morphologically similar to herpesvirus.

One of 14 goldfish (Carassius auratus) died 4 weeks after purchase and was investigated by necropsy and histological examination. Routine formalin fixation of the goldfish was followed by histopathology. Formalin fixed spleen and kidney from the fish was further processed by embedding in epoxy resin and examined by transmission electron microscopy (EM). Severe, diffuse necrosis of haematopoietic tissue in the spleen, thymus and kidney and severe, diffuse hyperplasia in the gill epithelial cells were seen. In the spleen there was severe, diffuse necrosis of lymphocytes and many nuclei with marginated chromatin and intranuclear inclusions were scattered throughout the necrotic tissue. EM of affected tissues demonstrated intranuclear particles morphologically similar to herpesvirus. The presence of an agent similar to a herpesvirus in a goldfish with severe haematopoietic necrosis suggests that the herpesvirus responsible for haematopoietic necrosis in cyprinid species throughout the world has entered the goldfish population in Australia.

Animals↗
PubMed2002

Atypical multiple, papilliform, xanthomatous, cutaneous neoplasia in a goose (Anser anser).

An 18-month-old, male greylag goose was presented for assessment of multiple, semi-pedunculated cutaneous masses limited to non-feathered areas of skin. Initial biopsy and histopathology revealed a mesenchymal neoplasm suggestive of lipoblastomatosis or atypical xanthoma. Immunohistochemistry was unsuccessful in determining the tissue type of origin. Surgical resection of all masses was prevented by the mucocutaneous location of several masses. Chemotherapy using intralesion cisplatin was unsuccessful in resolving the masses but was well-tolerated by the goose. Serum lipid and lipoprotein analysis revealed a persistent hypercholesterolaemia and hypertriglyceridaemia without biochemical evidence of an underlying metabolic disease. The persistent hyperlipidaemia may have contributed to the formation of the masses identified in this case.

Animals↗
PubMed2001

Genetic diversity of beak and feather disease virus detected in psittacine species in Australia.

The complete nucleotide (nt) sequence of eight isolates of beak and feather disease virus (BFDV) obtained from a range of psittacine species with psittacine beak and feather disease (PBFD) from throughout Australia were compared with the sequences of two BFDV isolates previously reported from Australia (BFDV-AUS) and America (BFDV-USA), respectively. All isolates had the same basic structure including the position of the open reading frames, the hairpin structure between ORF1 and ORF2, the nonanucleotide motif (TAGTATTAC) therein, the three motifs of Rep protein encoded from ORF1 and involved in rolling circle replication, and the P-loop motif previously described, but the genome size of the eight isolates ranged from 1992 to 2018 nt. Overall nt identity of the isolates compared to BFDV-AUS ranged from 84 to 97%; the variation was due to a combination of point mutations and a number of deletions and insertions ranging from 1 to 17 nt in size detected in both coding and noncoding regions. The identity of the nt sequence of ORF2 compared to BFDV-AUS varied from 80 to 99%, while the identity of the deduced amino acid sequences varied from 73 to 99%. Phylogenetic analysis grouped the isolates into four clusters but there were no apparent regional differences or differences related to the psittacine species of origin. While seven ORFs with the potential to encode proteins greater than 8.7 kDa were detected in the BFDV-AUS isolate described previously, only three of these ORFs were detected in all 10 BFDV isolates for which sequence data were available. The three ORFs were ORF1 that presumably encodes the Rep protein, ORF2 presumably the major capsid protein, and the ORF previously designated ORF5. The ORF5 was of two size classes in different isolates, 303 and 474 nt, and only the first 303 nt of the viruses with an ORF of 474 nt were common to the other isolates.

Amino Acid Sequence↗
PubMed2001

Normobaric hyperoxic stress in budgerigars: enzymic antioxidants and lipid peroxidation.

The effects of acute (3 h), repeated acute (3 exposures each of 3 h) and chronic (72 h) normobaric hyperoxic exposure in budgerigars (Melopsittacus undulatus) were evaluated by monitoring the effects on pulmonary enzymic antioxidants, and indicators of lipid peroxidation. All durations of oxygen exposure resulted in significant respiratory alkalosis and elevated pulmonary and blood glutathione peroxidase concentrations. The concentrations of other pulmonary enzymic antioxidants including glutathione reductase and superoxide dismutase were not significantly altered by oxygen exposure. Pulmonary concentrations of the lipid peroxidation markers malonaldehyde and 4-hydroxyalkenal were not significantly elevated following oxygen exposure. Plasma concentrations of 8-epi isoprostane F(2alpha) were significantly elevated following both acute and repeated acute exposure. The results indicate that in budgerigars, both acute and chronic oxygen exposure can result in significant alteration in respiratory function and increased production of reactive oxygen species.

Animals↗
PubMed2001

Normobaric hyperoxic stress in budgerigars: non-enzymic antioxidants.

The effects of oxygen exposure on pulmonary and blood non-enzymic antioxidant concentrations was evaluated in budgerigars (Melopsittacus undulatus). Budgerigars were exposed to acute (3 h), repeated acute (3 exposures each of 3 h) or chronic (72 h) normobaric hyperoxic environments and the pulmonary and plasma concentrations of selected non-enzymic antioxidants, namely glutathione, uric acid, alpha- and gamma-tocopherol and carotenoids were assayed. With increasing duration of oxygen exposure, the ratio of oxidised to reduced glutathione was significantly increased, while the concentrations of uric acid, alpha- and gamma-tocopherol and carotenoids were significantly reduced, especially following chronic oxygen exposure. Following acute and repeated acute exposure, alteration in glutathione concentrations and reduction in alpha-tocopherol concentrations indicated oxygen stress. Following chronic exposure, depletion of non-enzymic antioxidants indicated exhaustion of these protective mechanisms and progression from oxygen stress to oxygen toxicity.

Animals↗
PubMed2000

Cryptosporidium meleagridis in an Indian ring-necked parrot (Psittacula krameri).

OBJECTIVE: To perform a morphological and genetic characterisation of a Cryptosporidium infection in an Indian ring-necked parrot (Psittacula krameri) and to compare this with C meleagridis from a turkey. DESIGN: Tissue and intestinal sections from an Indian ring-necked parrot were examined microscopically for Cryptosporidium. The organism was also purified from the crop and intestine, the DNA extracted and a portion of the 18S rDNA gene amplified, sequenced and compared with sequence and biological information obtained for C meleagridis from a turkey as well as sequence information for other species of Cryptosporidium. RESULTS: Morphological examination of tissue sections from an Indian ring-necked parrot revealed large numbers of Cryptosporidium oocysts attached to the apical border of enterocytes lining the intestinal tract. Purified Cryptosporidium oocysts measured about 5.1 x 4.5 microns, which conformed morphologically to C meleagridis. The sequence obtained from this isolate was identical to sequence information obtained from a C meleagridis isolate from a turkey. CONCLUSION: Cryptosporidium meleagridis was detected in an Indian ring-necked parrot using morphological and molecular methods. This is the first time that this species of Cryptosporidium has been reported in a non-galliform host and extends the known host range of C meleagridis.

Animals↗
PubMed1999

A universal polymerase chain reaction for the detection of psittacine beak and feather disease virus.

A universal PCR assay was designed that consistently detected psittacine beak and feather disease virus (BFDV) in psittacine birds affected with psittacine beak and feather disease (PBFD) from different geographic regions across Australia. Primers within open reading frame 1 (ORF1) of the BFDV genome consistently amplified a 717 bp product from blood and/or feathers of 32 birds with PBFD lesions. The PCR did not amplify a product from the feathers or blood from 7 clinically normal psittacine birds. Primers based on regions outside of ORF1 did not consistently produce a PCR product, suggesting there was some genomic variation outside ORF1. The amplified ORF1 PCR products of 10 BFDV isolates, from different psittacine species and from various regions around Australia, were cloned and comparative DNA sequence analysis demonstrated 88-99% of the ORF1 fragments. The derived amino acid sequences of the amplified ORF1 fragments demonstrated similar identity between all 10 isolates. Within ORF1, there was complete conservation of the putative nucleotide binding site and marked conservation of 2 other motifs previously identified as essential components of the replication-associated proteins of other circoviruses and geminiviruses.

Amino Acid Sequence↗
PubMed1998

Psittacine beak and feather disease virus nucleotide sequence analysis and its relationship to porcine circovirus, plant circoviruses, and chicken anaemia virus.

Cloning and sequencing of the circular, single-stranded DNA of one isolate of psittacine beak and feather disease virus (BFDV) demonstrate a genome composed of a circular molecule of 1993 nucleotide bases. An analysis of the assembled replicative form demonstrated seven open reading frames (ORFs) (three in the virion strand and four in the complementary strand), potentially encoding seven viral proteins of >8.7 kDa. High amino acid sequence similarity was demonstrated between a potential 33.3-kDa protein product of ORF1 of BFDV and the replicase-associated protein of porcine circovirus (PCV), subterranean clover stunt virus, and faba bean necrotic yellows virus. However, significant similarity in nucleotide or amino acid sequences was not present between BFDV and chicken anaemia virus. A potential stem-loop structure similar to that found in PCV and plant circoviruses was present in the putative encapsidated strand of the BFDV genome. At the top of this structure, a nonanucleotide motif (TAGTATTAC) similar to that of PCV, plant circoviruses, and geminiviruses also was recognised. Comparison of the deduced amino acid sequences of ORF2 of BFDV and PCV demonstrated 29.1% identity, and in both viruses, ORF2 is located on the complementary strand, beginning close to or within the hairpin stem. Our findings provide further evidence of a close relationship among BFDV, PCV, and plant circoviruses but not chicken anaemia virus.

Amino Acid Sequence↗
PubMed1998

Skin disease affecting the conservation of the western swamp tortoise (Pseudemydura umbrina)

OBJECTIVE: To review the present position of the western swamp tortoise (Pseudemydura umbrina) as an endangered species and significant health issues affecting efforts to save it from extinction. PROCEDURE: A retrospective analysis of the husbandry, hospital and pathology records of the western swamp tortoise captive breeding program at Perth Zoo. RESULTS: In 1987 a captive breeding project was developed to prevent the extinction of the western swamp tortoise but an outbreak of a necrotising dermatitis in 1989 threatened the survival of the captive bred hatchlings. Less severe outbreaks occurred in 1990 and 1993, with isolated cases in between. Of 283 tortoises that were born in captivity or came into captivity from the wild, 37 (13.1%) were affected, comprising 37% of all males, 26% of all females and 13% of animals of unknown gender. Of the affected animals, 70% were less than 2 years of age and 29% were older. Males were 1.6 times more likely to be infected than females but this difference was not statistically significant (P = 0.27). Culture of the lesions consistently yielded unidentified Pseudomonas sp. CONCLUSION: Improved husbandry, such as strict maintenance of water quality and temperature conditions similar to that of the animal's natural habitat, and monitoring the health of individual tortoises have successfully controlled skin disease in the captive breeding of the western swamp tortoise.

Animals↗
PubMed1998

Gram-negative bacterial infections and cardiovascular parasitism in green sea turtles (Chelonia mydas).

OBJECTIVE: To investigate causes of ill health and mortality in juvenile wild green sea turtles (Chelonia mydas) found along the mid-north west coast of Western Australia between June and October of 1997. PROCEDURE: Department of Conservation and Land Management rangers submitted four dead or dying green sea turtles from separate incidents for veterinary examination, necropsy, and bacteriological, parasitological and histopathological examination. RESULTS: Numerous different species of trematodes belonging to the families Pronocephalidae, Microscaphidiidae and Paramphistomidae were detected in the intestines of two turtles examined, and in all turtles there was severe spirorchid fluke infection including Haemoxenicon sp, Amphiorchis sp and Hapalotrema sp. Histopathological examination demonstrated severe multifocal to diffuse granulomatous vasculitis, aggregations of spirorchid fluke eggs and microabscesses throughout various tissues including intestines, kidney, liver, lung and brain. Cultures and or histopathological examination demonstrated disseminated Gram-negative bacterial infections including salmonella, E coli, Citrobacter freundii and Moraxella sp. CONCLUSION: Infections caused by salmonellae, E coli and other Gram-negative bacteria should be considered as causes of systemic illness and death in wild green sea turtles infected with spirorchid cardiovascular flukes and other internal parasites.

Animals↗
PubMed1997

Trichomonas gallinae in budgerigars and columbid birds in Perth, Western Australia.

OBJECTIVE: To estimate the prevalence of infection with Trichomonas gallinae and other parasites of the alimentary tract in psittacine and columbid birds in Perth and to determine in vitro the effectiveness of drugs commonly recommended for treating trichomoniasis. DESIGN AND PROCEDURES: Samples of crop contents were collected from aviary flocks of budgerigars (Melopsittacus undulatus) and other psittacine and columbid birds in both private and commercial collections in Perth. Similar samples from wild Senegal doves (Streptopelia senegalensis) also were collected. Crop contents were examined and cultured for Trichomonas gallinae and in vitro studies were conducted on the susceptibility of isolates to several drugs used commonly. Other parasites also were detected by faecal examination and/or necropsy. RESULTS: T gallinae was recovered from birds in 1 of 13 private collections of budgerigars (2/289 birds in total). Direct wet-mount examination of crop fluid identified 36.4% of samples at four commercial bird dealers which were later determined by culture to contain T gallinae. The prevalence of T gallinae infection range from 0 to 11.4% in budgerigars. The prevalence of T gallinae infection of wild Senegal doves was 46% and from one flock of racing pigeons was 59%. The in vitro minimum lethal concentrations of metronidazole, dimetridazole and ronidazole ranged from 40 to 96, 30 to 80 and 40 to 92 micrograms/mL respectively for six isolates of T gallinae. Other alimentary parasites detected during the survey included Spironucleus sp (syn. Hexamita sp), coccidia, Ascaridia platycerci and Raillietina sp. CONCLUSIONS: Thirteen budgerigar flocks belonging to members of avicultural societies in Perth had a low prevalence of trichomoniasis and other parasitic infections. The dose rate currently recommended for ronidazole may not result in complete protozoacidal activity against T gallinae infection.

Animals↗