Sea lice Lepeophtheirus spinifer, Tuxophorus sp. and Caligus sp. infections on wild-caught queenfish Scomberoides commersonnianus from northern Australia.

Studies of ectoparasites of wild-caught queenfish Scomberoides commersonnianus from several areas in northern Australia were reviewed to investigate relationships between parasite burdens, environmental conditions and external lesions. A sample of 27 queenfish captured near a dredge spoil disposal site in Gladstone Harbour, Queensland, Australia, in January 2012 was anomalous, with a high percentage of fish (66.6%) exhibiting grossly visible skin lesions including foci of erythema and petechial haemorrhages, particularly on the pectoral girdle and ventrolateral surfaces. Microscopically, lesions comprised acute epidermal erosion, ulceration and/or perivascular dermatitis with dermal oedema and depigmentation. Skin lesions were associated with high prevalence (100%) and intensity (mean = 21.2 copepods fish-1, range 4-46) of infection by sea lice Lepeophtheirus spinifer. Only queenfish infected with >10 L. spinifer presented with skin lesions. This is the first record of L. spinifer from Australia. In contrast, grossly visible skin lesions were not reported from queenfish (n = 152) sampled from other sites in the Northern Territory and Queensland, where the sampled fish had a much lower prevalence (51.3%) and intensity (mean = 3.54, range 0-26) of copepod (L. spinifer, Caligus spp. and Tuxophorus sp.) infections. Copepods from queenfish in studies undertaken outside Gladstone Harbour exhibited an over-dispersed pattern of infection, with the vast majority (n = 137, or 90.1%) of fish infected with <5 copepods. These data demonstrate that heavy L. spinifer infections, combined with poor water quality and/or direct exposure to contaminated dredge spoil and blooms of the cyanobacterium Lyngbya majuscula, can be associated with cutaneous disease in wild-caught queenfish.

Post-mortem examination of the Caribbean spiny lobster (Panulirus argus, Latreille 1804) and pathology in a fishery of the Lesser Antilles.

The Caribbean spiny lobster, Panulirus argus (Latreille, 1804) is a highly commercial species and comprises the largest spiny lobster fishery in the world. Although populations have declined throughout its range, there is little known regarding its diseases and pathogens. The objectives of this study were to provide illustrated and standardized methods for postmortem examination, and to describe baseline gross and microscopic pathology for P. argus. From July 2017-March 2019, a postmortem examination including comprehensive histological assessment was performed on 313 fishery-caught lobsters. Epibionts and lesions observed include branchial cirriped infestation (69%), branchial encysted nemertean worm larvae (23%), tail fan necrosis (11%), skeletal muscle necrosis (7%), antennal gland calculi (6%), branchial infarction (2%), and microsporidiosis (0.6%). This report confirms the rare prevalence of microsporidiosis in P. argus and describes nemertean worm larvae in the gill. This study also reports a condition resembling excretory calcinosis in spiny lobster. The methods and data produced by this study facilitate disease diagnosis and sustainable stock management of P. argus.

Epizootics of Streptococcus agalactiae infection in captive rays from Queensland, Australia.

The aim of this study was to describe two epizootics of high mortalities from infection with Streptococcus agalactiae, occurring in captive rays held in a marine display aquarium in south-east Queensland, Australia, in 2009 and 2010. Five different species of rays were affected, including mangrove whiprays (Himantura granulata), estuary rays (Dasyatis fluviorum), eastern shovelnose rays (Aptychotrema rostrata), white-spotted eagle rays (Aetobatus narinari) and blue-spotted mask rays (Neotrygon kuhlii). This report describes the history of both epizootics including collection, quarantine and husbandry of rays, the disease epizootics, clinico-pathological features of the disease, antimicrobial therapy, autogenous vaccine production, and laboratory studies including clinical and histopathology, bacteriology, PCR, molecular serotyping and sequencing of the bacterium S. agalactiae.

Pathology of finfish and mud crabs Scylla serrata during a mortality event associated with a harbour development project in Port Curtis, Australia.

The objective of this study was to assess the extent and describe the nature of a multi-species marine finfish and crustacean disease event that occurred in Gladstone Harbour, Australia, 2011-2012. Finfish were examined for this study in January to April 2012 from sites where diseased animals were previously observed by the public. Gross abnormalities, including excessive skin and gill mucus, erythema, heavy ecto-parasitism, cutaneous ulceration, corneal opacity, and exophthalmos, were higher (25.5%) in finfish from Gladstone Harbour (n = 435) than in those from an undeveloped reference site, 250 km to the north (5.5%, n = 146, p < 0.0001). Microscopic abnormalities, especially non-infectious erosive to ulcerative dermatitis and internal parasitism, were more prevalent in fish from Gladstone Harbour (n = 34 of 36, prevalence = 94.4%) than in fish from the reference site (3 of 23, prevalence = 13.0% p < 0.0001). The prevalence of shell lesions was higher in mud crabs Scylla serrata sampled from Gladstone Harbour (270 of 718, prevalence = 37.5%) than from the reference site (21 of 153, prevalence = 13.7%; p < 0.0001). The significantly higher prevalence of ulcerative skin disease and parasitism in a range of species suggests affected animals were subjected to influences in Gladstone Harbour that were not present in the control sites. The disease epidemic coincided temporally and spatially with water quality changes caused by a harbour development project. The unique hydrology, geology, and industrial history of the harbour, the scope of the development of the project, and the failure of a bund wall built to retain dredge spoil sediment were important factors contributing to this epidemic.

Case-control study of epidemic mortality and Cardicola forsteri-associated disease in farmed southern bluefin tuna (Thunnus maccoyii) of South Australia.

Cardicola forsteri is a blood fluke that is highly prevalent among cultured southern bluefin tuna (SBT), Thunnus maccoyii, in South Australia. The role of C forsteri in annual SBT mortality outbreaks, which peak 6 to 12 weeks poststocking, is unknown. The objective of this study was to identify lesions unique to cultured SBT that died during a mortality event in 2009 and to determine the significance of C forsteri-associated lesions. Cultured SBT were sampled from 4 pontoons of a single site in Spencer Gulf that experienced a mortality epidemic that spanned 5 to 14 weeks poststocking. Study SBT comprised 7 that died during peak mortality, 27 that did not die, and 10 wild-caught (noncultured) SBT. All cultured SBT had branchitis and myocarditis due to C forsteri, whereas no life stages of C forsteri were histologically identified in any wild-caught SBT. Mortality was associated with the presence of severe branchitis (P<.005), and the odds of severe branchitis were 90 times greater for SBT that died than for SBT that were live caught during peak mortality (95% confidence interval, 5 to 1,684). In SBT that had died, no lesions other than those associated with C forsteri were of sufficient severity or physiologic significance to account for death. Other lesions common among cultured SBT included systemic granulocytic perivascular infiltrate, granulocytic gastric infiltrate, hepatic lipidosis, visceral granulomas, and branchial parasitic infestation. This study shows for the first time that a substantial proportion of poststocking mortality in cultured SBT is strongly associated with severe branchitis caused by C forsteri.

Longitudinal study of clinicopathological features of Johne's disease in sheep naturally exposed to Mycobacterium avium subspecies paratuberculosis.

The objective of this study was to describe chronological changes in infection status and enteric lesions of sheep naturally exposed to Mycobacterium avium subspecies paratubercuolosis. Samples of terminal ileum (TI) and mesenteric lymph node (MLN) were collected from 77 Merino sheep via surgical biopsy at 12, 18, and 24 months of age and necropsy at 36 months of age. Infection status at each sampling period was determined by fecal, TI, and MLN culture. Quantitative grading schemes were used to gauge the severity of granulomatous inflammation and degree of mycobacterial colonization affecting TI and MLN sections. Incidences of infection and disease were steady throughout the study; 46 of the 77 (59.7%) sheep became infected, and 30 of the 77 (39.0%) developed Johne's disease. Infection was first detected after 18 months of age in many sheep, and age when infection was first detected was not associated with clinical outcome. Culture of MLN detected 44 of the 46 (95.6%) infected sheep and initial lesions always involved MLN. Sheep typically developed lesions within 6-12 months following detection of infection by culture. The severity of enteritis and mycobacterial colonization progressed at variable rates among sheep. Severe multibacillary enteritis never regressed, and affected sheep expressed clinical signs within the following 12 months. Lymphocyte-rich paucibacillary enteritis was observed in 3 sheep, causing clinical signs in one and progressing to severe multibacillary enteritis in another. Six of the 46 (8.7%) biopsy-culture-positive sheep later had negative cultures at necropsy, suggesting recovery from infection. Further study is needed to identify factors associated with clearance of infection or progression of disease.

Prognostic factors for cutaneous and subcutaneous soft tissue sarcomas in dogs.

Soft tissue sarcomas (STSs) develop from mesenchymal cells of soft tissues, and they commonly occur in the skin and subcutis of the dog. Although phenotypically diverse with frequently controversial histogenesis, STSs are considered as a group because they have similar features microscopically and clinically. Following resection, local recurrence rates are low in general but vary according to histologic grade and completeness of surgical margins. Complete margins predict nonrecurrence. Even most grade I STSs with "close" margins will not recur, but propensity for recurrence increases with grade. The frequency of metastasis has not been accurately estimated, but it is believed to be rare for grade I STSs and most likely to occur with grade III STSs. However, metastasis does not necessarily equate with poor survival. High mitotic index is prognostic for reduced survival time. Further research is needed to determine more precise estimates for recurrence rates and survival as related to completeness of surgical margins and to delineate potential differences in metastatic rate and median survival time between grades. Other potential indicators of prognosis that presently require further investigation include histologic type, tumor dimension, location, invasiveness, stage, markers of cellular proliferation, and cytogenetic profiles. Common issues limiting prognostic factor evaluation include biases from retrospective studies, small sample sizes, poor verification of metastasis, inconsistent STS classification and use of nomenclature, difficulties in differentiating STS phenotype, and diversity of the study population (stage of disease and treatment status).

Recommended guidelines for the conduct and evaluation of prognostic studies in veterinary oncology.

There is an increasing need for more accurate prognostic and predictive markers in veterinary oncology because of an increasing number of treatment options, the increased financial costs associated with treatment, and the emotional stress experienced by owners in association with the disease and its treatment. Numerous studies have evaluated potential prognostic and predictive markers for veterinary neoplastic diseases, but there are no established guidelines or standards for the conduct and reporting of prognostic studies in veterinary medicine. This lack of standardization has made the evaluation and comparison of studies difficult. Most important, translating these results to clinical applications is problematic. To address this issue, the American College of Veterinary Pathologists' Oncology Committee organized an initiative to establish guidelines for the conduct and reporting of prognostic studies in veterinary oncology. The goal of this initiative is to increase the quality and standardization of veterinary prognostic studies to facilitate independent evaluation, validation, comparison, and implementation of study results. This article represents a consensus statement on the conduct and reporting of prognostic studies in veterinary oncology from veterinary pathologists and oncologists from around the world. These guidelines should be considered a recommendation based on the current state of knowledge in the field, and they will need to be continually reevaluated and revised as the field of veterinary oncology continues to progress. As mentioned, these guidelines were developed through an initiative of the American College of Veterinary Pathologists' Oncology Committee, and they have been reviewed and endorsed by the World Small Animal Veterinary Association.

Recommended guidelines for submission, trimming, margin evaluation, and reporting of tumor biopsy specimens in veterinary surgical pathology.

Neoplastic diseases are typically diagnosed by biopsy and histopathological evaluation. The pathology report is key in determining prognosis, therapeutic decisions, and overall case management and therefore requires diagnostic accuracy, completeness, and clarity. Successful management relies on collaboration between clinical veterinarians, oncologists, and pathologists. To date there has been no standardized approach or guideline for the submission, trimming, margin evaluation, or reporting of neoplastic biopsy specimens in veterinary medicine. To address this issue, a committee consisting of veterinary pathologists and oncologists was established under the auspices of the American College of Veterinary Pathologists Oncology Committee. These consensus guidelines were subsequently reviewed and endorsed by a large international group of veterinary pathologists. These recommended guidelines are not mandated but rather exist to help clinicians and veterinary pathologists optimally handle neoplastic biopsy samples. Many of these guidelines represent the collective experience of the committee members and consensus group when assessing neoplastic lesions from veterinary patients but have not met the rigors of definitive scientific study and investigation. These questions of technique, analysis, and evaluation should be put through formal scrutiny in rigorous clinical studies in the near future so that more definitive guidelines can be derived.

Histopathological survey of lesions and infections affecting sick ornamental fish in pet shops in New South Wales, Australia.

The objective of this study was to describe the frequency of histopathological lesions and categorize histopathologically evident infections in sick ornamental fish from pet shops in New South Wales, Australia. We examined 108 fish that had evidence of morbidity or mortality, including 67 cyprinids, 25 osphronemids, 11 poeciliids, 4 characids and 1 cichlid, sourced from 24 retail outlets. Conditions frequently observed in the study population included branchitis (62/86, 72.1%), visceral granulomas (41/108, 38.0%), dermatitis (17/55, 30.9%), wasting (31/108, 28.7%), and intestinal coccidiosis (18/104, 17.4 %). Branchitis and dermatitis were usually due to monogenean flukes, or flagellate or ciliate protozoa. Intralesional Microsporidia (16/41, 39.0%), mycobacteria (7/41, 17.%), or Myxosporidia (5/41, 12.2%) were identified in the majority of fish with visceral granulomas; however, special stains were critical in their identification. The proportion of histologically evident infections was remarkably high (77/108, 71.3%), and parasitic infections predominated. Many pathogens identified in the study have low host specificity and/or direct life cycles which would facilitate transmission to exposed naive fish populations, potentially posing a threat to native and commercial fish populations. Those caring for sick ornamental fish should take appropriate steps to investigate infectious disease and should take precautions that prevent the spread of pathogens.

Iridovirus infections in finfish - critical review with emphasis on ranaviruses.

Viruses in three genera of the family Iridoviridae (iridoviruses) affect finfish. Ranaviruses and megalocytiviruses are recently emerged pathogens. Both cause severe systemic disease, occur globally and affect a diversity of hosts. In contrast, lymphocystiviruses cause superficial lesions and rarely cause economic loss. The ranavirus epizootic haematopoietic necrosis virus (EHNV) from Australia was the first iridovirus to cause epizootic mortality in finfish. Like other ranaviruses, it lacks host specificity. A distinct but closely related virus, European catfish virus, occurs in finfish in Europe, while very similar ranaviruses occur in amphibians in Europe, Asia, Australia, North America and South America. These viruses can be distinguished from one another by conserved differences in the sequence of the major capsid protein gene, which informs policies of the World Organisation for Animal Health to minimize transboundary spread of these agents. However, limited epidemiological information and variations in disease expression create difficulties for design of sampling strategies for surveillance. There is still uncertainty surrounding the taxonomy of some putative ranaviruses such as Singapore grouper iridovirus and Santee-Cooper ranavirus, both of which cause serious disease in fish, and confusion continues with diseases caused by megalocytiviruses. In this review, aspects of the agents and diseases caused by ranaviruses are contrasted with those due to megalocytiviruses to promote accurate diagnosis and characterization of the agents responsible. Ranavirus epizootics in amphibians are also discussed because of possible links with finfish and common anthropogenic mechanisms of spread. The source of the global epizootic of disease caused by systemic iridoviruses in finfish and amphibians is uncertain, but three possibilities are discussed: trade in food fish, trade in ornamental fish, reptiles and amphibians and emergence from unknown reservoir hosts associated with environmental change.

Association of severity of enteric granulomatous inflammation with disseminated Mycobacterium avium subspecies paratuberculosis infection and antemortem test results for paratuberculosis in dairy cows.

Disseminated infection (DI) of Mycobacterium avium subspecies paratuberculosis (MAP) in cattle may impair cow health, potentiate spread of disease, and is a potential food-safety risk. The objectives of this study were to determine the association between severity of histologic enteric lesions and the occurrence of DI, clinical signs, and positive fecal culture and serum ELISA results. Bacteriologic fecal culture and serum ELISA were performed on 40 dairy cows from MAP-infected herds. Cows were classified as having DI if MAP was isolated from any of 11 extra-intestinal tissues collected postmortem. A grade of 0-3, corresponding to the severity of histologically evident granulomatous inflammation was determined for sections of ileum, jejunum, mesenteric lymph node, and ileocolic lymph node. An overall intestinal inflammation (OII) grade of 0-3 was assigned to each cow. The proportion of cows with DI increased with tissue-specific lesion grade and OII grade. All cows with grade 3 inflammation in any single tissue had DI, however, some cows with DI had grade 1 inflammation or no lesions. In general, there was a positive association between OII grade and clinical signs, gross enteric lesions, and positive ELISA and fecal culture results. However, 12% of OII grade 0 cows had clinical signs (explained by other conditions recognized with necropsy), and the proportion of positive ELISA results was lower for OII grade 3 cows relative to grade 2 cows. Although MAP dissemination may occur early in the disease process, histopathology of intestinal tissues may be used to detect a substantial proportion of DI cows.

Squamous cell carcinoma with hepatic metastasis in a saltwater crocodile (Crocodylus porosus).

BACKGROUND: Squamous cell carcinomas (SCC) are uncommon in reptiles and there have been few reports of neoplasia in Australian crocodiles, despite increased numbers being raised in captivity. CASE REPORT: We report a locally invasive SCC in the hindlimb of a wild-caught saltwater crocodile (Crocodylus porosus) with hepatic metastasis. The gross appearance was soft tissue swelling adjacent to the nail bed, progressing to abscessation incorporating multiple toes. Diagnosis was achieved by biopsy during amputation of the affected toes. Hepatic metastasis was identified at necropsy, with a similar gross appearance resembling an abscess. CLINICAL SIGNIFICANCE: Neoplasia is an uncommon finding in crocodilians and metastatic neoplasia is rarely documented. This is the first report of SCC in a crocodilian.

Laboratory-controlled Challenges of Nile Tilapia (Oreochromis niloticus) with Streptococcus agalactiae: Comparisons between Immersion, Oral, Intracoelomic and Intramuscular Routes of Infection.

Streptococcus agalactiae, the aetiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. To gain a better understanding of the pathogenesis of streptococcosis in Nile tilapia (Oreochromis niloticus), and to identify the experimental route of infection that most closely mimics natural disease, fingerlings were challenged with S. agalactiae utilizing different delivery methods. Fingerlings were challenged via intracoelomic injection (ICinj), intramuscular injection (IMinj), orally or by immersion with serial dilutions of S. agalactiae. The dose lethal to 50% of test fish 15 days post challenge was 120 colony forming units (CFU)/fish after ICinj, and 105 CFU/fish after IMinj. Acute mortalities were present in both groups, but were higher in the fish challenged by ICinj. Very low mortalities were observed in the fish challenged via oral or immersion routes. Post-mortem evaluation of survivors revealed classical lesions associated with fish streptococcosis, including granulomatous or lymphohistiocytic epicarditis, splenitis, meningitis, myocarditis, choroiditis and exophthalmia. The information obtained improves our understanding of the pathogenesis of streptococcosis in fish, and provides useful information regarding controlled experimental infections in tilapia challenged with S. agalactiae. Results from this study suggest that IMinj challenge methods are not only suitable to induce streptococcosis in tilapia, but they may be the preferred method to study the pathogenesis of the naturally-occurring disease in this species.

Hypofractionated radiation therapy for the treatment of microscopic canine soft tissue sarcoma.

Soft tissue sarcomas (STSs) are locally invasive and surgery with or without radiation therapy is the current standard of care in dogs. Typical protocols for treating incompletely excised STSs involve curative intent radiation with total dose in excess of 50 Gy. Forty-eight dogs with histologically confirmed incomplete or closely excised STSs were treated with a hypofractionated protocol that is typically reserved for palliative radiation therapy (RT) (6-8 Gy/weekly fractions to a total dose of 24-32 Gy). Ten dogs (21%) developed local recurrence, 11 dogs (23%) developed metastasis, and 3 dogs developed both (included in each group). The median progression free survival was 698 days. The local failure-free probability at 1 and 3 years was 81 and 73%. The 1 and 3 years tumour-specific overall survival was 81 and 61%. Long-term local tumour control was achieved in the majority of dogs. This protocol is reasonable to prescribe in older patients or when financial limitations exist.

The Basic Knowledge Assessment Tool (BKAT) for critical care nursing: its use and effect on orientation programs.

Findings from this study of 54 subjects who used the BKAT-3 in their professional practice indicate that it is being used most frequently in orientation programs conducted in critical care units, and that content and scores of the BKAT have resulted in changes in those programs. Scores are also being used for placement of nurses with previous critical care experience. In addition, findings from this study and from the literature indicate that research continues to be conducted using scores on the BKAT as a dependent variable, and that moderate to moderately high correlations exist between intended and actual use of the BKAT.

Competent i.v. management, Part 1.

Review two court cases regarding common pitfalls and current legal trends of i.v. management.

Competent i.v. management, Part 2.

Implementation of fundamental principles and practice standards regarding peripheral i.v. therapy reduces the risks of patient injury and litigation.

Extensive epidermal naevus in a foal.

CASE REPORT: A 2-month-old Standardbred filly was presented for examination and treatment of extensive congenital skin lesions that had a linear distribution on the left front leg extending from the dorsal midline to the metacarpal region. The lesions were surgically excised under general anaesthesia. Surgical excision was curative and there were no signs of recurrence 6 weeks after surgery. The number and distribution of lesions were more extensive than in previously reported cases of congenital papillomas, which have also been described as epidermal growth abnormalities (naevi or hamartomas). Early reports of congenital papillomas suggest in-utero infection with papillomavirus may be responsible, despite a lack of histological features associated with papillomavirus infection. Papillomavirus immunohistochemistry has subsequently proven negative in tested cases. CONCLUSIONS: The presence at birth, their appearance and the extensive distribution of lesions in this case is similar to verrucous epidermal naevus of humans. A name change from congenital papilloma to epidermal naevus is proposed for this condition in horses.