N. Stephens

Cetacean Morbillivirus: Current Knowledge and Future Directions

We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported.

The pathology and pathogenicity of a novel Haemoproteus spp. infection in wild Little Penguins (Eudyptula minor)

One hundred and thirty four Little Penguin (Eudyptula minor) carcases found since 2004 in south west Australia were necropsied. The livers and spleens from ten of the penguins exhibited varying degrees of multifocal, randomly scattered areas of necrosis and varying numbers of parasites were associated with these areas. Hepatomegaly and splenomegaly were noted in many of these ten cases. Necrosis and parasites were also observed in the cardiac muscle of four of the cases and in the lung tissue in one of the penguins. Using PCR, the parasites were positively identified in four of the cases as Haemoproteus spp. and morphologically identical tissue stage parasites associated with histopathological changes were observed in all ten dead penguins. This is the first study to demonstrate both the in situ presence of the Haemoproteus parasite in any member of the Sphensicidae family and mortality due to its presence. We postulate the involvement of anomalous environmental conditions in a potential increase in local vectors.

Reversible control by vitamin D of granulocytes and bacteria in the lungs of mice: an ovalbumin-induced model of allergic airway disease.

Vitamin D may be essential for restricting the development and severity of allergic diseases and asthma, but a direct causal link between vitamin D deficiency and asthma has yet to be established. We have developed a ‘low dose’ model of allergic airway disease induced by intraperitoneal injection with ovalbumin (1 µg) and aluminium hydroxide (0.2 mg) in which characteristics of atopic asthma are recapitulated, including airway hyperresponsiveness, antigen-specific immunoglobulin type-E and lung inflammation. We assessed the effects of vitamin D deficiency throughout life (from conception until adulthood) on the severity of ovalbumin-induced allergic airway disease in vitamin D-replete and -deficient BALB/c mice using this model. Vitamin D had protective effects such that deficiency significantly enhanced eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male but not female mice. Vitamin D also suppressed the proliferation and T helper cell type-2 cytokine-secreting capacity of airway-draining lymph node cells from both male and female mice. Supplementation of initially vitamin D-deficient mice with vitamin D for four weeks returned serum 25-hydroxyvitamin D to levels observed in initially vitamin D-replete mice, and also suppressed eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male mice. Using generic 16 S rRNA primers, increased bacterial levels were detected in the lungs of initially vitamin D-deficient male mice, which were also reduced by vitamin D supplementation. These results indicate that vitamin D controls granulocyte levels in the bronchoalveolar lavage fluid in an allergen-sensitive manner, and may contribute towards the severity of asthma in a gender-specific fashion through regulation of respiratory bacteria.

Cetacean Morbillivirus in Coastal Indo-Pacific Bottlenose Dolphins, Western Australia

Cetacean morbillivirus (CeMV) has caused several epizootics in multiple species of cetaceans globally and is an emerging disease among cetaceans in Australia. We detected CeMV in 2 stranded coastal Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Western Australia. Preliminary phylogenetic data suggest that this virus variant is divergent from known strains.

Anthropogenic trauma is the most prevalent cause of mortality in Little Penguins (Eudyptula minor) in Perth, Western Australia

Abstract Penguins both forage and travel in the marine environment and so spend a much greater proportion of their lives in this environment than other seabirds. This maximises their exposure to an increasing range of threats compared with other seabirds. From late 2003 to 2012, necropsies were performed on 159 Little Penguins found in the Perth region, Western Australia. Given the close proximity of the colonies to increasingly populated urban areas, the aims of this study were to: (1) determine the causes of mortality; (2) determine the proportion of deaths attributable to anthropogenic causes; (3) use this information to help guide management strategies; and (4) identify potential threats to coastal seabirds in general. In most cases, cause of mortality could be assigned to one of 11 categories. Trauma, most likely from watercraft, was the main cause of mortality. The next most common cause, starvation, was more likely to occur in spring and summer. Management strategies for colonies of Little Penguins near high levels of watercraft activity should take into account the risk of injury or death from watercraft strikes.

WITHDRAWN: Corrigendum to "The pathology and pathogenicity of a novel Haemoproteus spp. infection in wild Little Penguins (Eudyptula minor)" [Vet. Parasitol. 197 (1-2) (2013) 74-84].

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.vetpar.2014.07.021. The duplicate article has therefore been withdrawn.

The invisible harm: land clearing is an issue of animal welfare

Abstract. Land clearing is a significant environmental issue in Australia and an area of active legislative reform. Despite evidence of the harm that land clearing causes to individual animals, such harm is either ignored or considered only indirectly in environmental decision-making. We argue that the harm that land clearing causes to animals ought to be identified and evaluated in decision-making relating to land clearing and consider the following three propositions in support: (1) land clearing causes deaths that are physically painful and psychologically distressing because of their traumatic and debilitating nature; (2) land clearing causes physical injuries, other pathological conditions, pain and psychological distress over a prolonged period as animals attempt to survive in the cleared environment or in the environments they are displaced to; and (3) on the basis of current clearing rates, more than 50 million mammals, birds and reptiles are likely to be killed annually because of land clearing in Queensland and New South Wales. The scientific consensus about the harm caused by land clearing means that decisions to allow land clearing are decisions to allow most of the animals present to be killed and, as such, frameworks for decision-making ought to include proper evaluation of the harm to be imposed.

Postmortem diagnosis of canine diabetes mellitus and diabetic ketoacidosis via biochemical analysis of aqueous humour

An adult male crossbreed canine cadaver of unknown age was presented for postmortem examination. The dog was found by animal welfare workers in a backyard, laterally recumbent with weak agonal breathing, which ceased during retrieval. No previous medical history was known. Postmortem urinalysis revealed hypersthenuria, severe bilirubinuria, severe glucosuria, significant haematuria and severe ketonuria (β-hydroxybutyrate). Serum biochemistry was not possible due to severe haemolysis; however analysis of aqueous humour revealed high concentrations of β-hydroxybutyrate, glucose, total bilirubin, urea and creatine. Severe diffuse hepatic lipidosis with severe intrahepatic cholestasis and jaundice, poor body condition and bilateral cataracts were identified on gross and histological examination. These findings are supportive of chronic diabetes mellitus with acute ketoacidosis resulting in death. As such, the authors propose that biochemical analysis of aqueous humour/ocular fluids can be considered for postmortem diagnosis of diabetes mellitus and diabetic ketoacidosis in dogs.