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Dive into the research topics where C. Holyoake is active.

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Featured researches published by C. Holyoake.


Emerging Infectious Diseases | 2014

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

N. Stephens; Pádraig J. Duignan; Jianning Wang; John Bingham; H. Finn; I Lars Bejder; Anthony P. Patterson; C. Holyoake

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.


PLOS ONE | 2016

Isotopic evidence of a wide spectrum of feeding strategies in Southern hemisphere humpback whale baleen records

Pascale Eisenmann; Brian Fry; C. Holyoake; Douglas Coughran; Steve Nicol; Susan Bengtson Nash

Our current understanding of Southern hemisphere humpback whale (Megaptera novaeangliae) ecology assumes high-fidelity feeding on Antarctic krill in Antarctic waters during summer, followed by fasting during their annual migration to and from equatorial breeding grounds. An increase in the number of reported departures from this feeding/fasting model suggests that the current model may be oversimplified or, alternatively, undergoing contemporary change. Information about the feeding and fasting cycles of the two Australian breeding populations of humpback whales were obtained through stable isotope analysis of baleen plates from stranded adult individuals. Comparison of isotope profiles showed that individuals from the West Australian breeding population strongly adhered to the classical feeding model. By contrast, East Australian population individuals demonstrated greater heterogeneity in their feeding. On a spectrum from exclusive Antarctic feeding to exclusive feeding in temperate waters, three different strategies were assigned and discussed: classical feeders, supplemental feeders, and temperate zone feeders. Diversity in the inter-annual feeding strategies of humpback whales demonstrates the feeding plasticity of the species, but could also be indicative of changing dynamics within the Antarctic sea-ice ecosystem. This study presents the first investigation of trophodynamics in Southern hemisphere humpback whales derived from baleen plates, and further provides the first estimates of baleen plate elongation rates in the species.


New Zealand Veterinary Journal | 2014

Clinical beak and feather disease virus infection in wild juvenile eastern rosellas of New Zealand; biosecurity implications for wildlife care facilities

Bethany Jackson; C. Harvey; Josie A. Galbraith; M Robertson; K. Warren; C. Holyoake; Laurel Julian; Arvind Varsani

Abstract CASE HISTORY: Four juvenile eastern rosellas (Platycercus eximius) were admitted to two separate wildlife care facilities in the Auckland region by members of the public. They had missing or dystrophic wing and tail feathers that rendered them flightless, suggestive of beak and feather disease virus (BFDV) infection. Two were subject to euthanasia after failing to re-grow their feathers, with samples taken for histopathology and PCR analysis. Blood samples were obtained from the other two birds at the time of examination, however these individuals were lost to follow up. PATHOLOGICAL AND MOLECULAR FINDINGS: Basophilic inclusion bodies were observed in histological sections of the feather bulb, typical of BFDV infection, from the two euthanised individuals. Blood from all four birds tested positive by PCR for BFDV, and analysis of the recovered full BFDV genomes identified them as belonging to the BFDV-A strain. DIAGNOSIS: Beak and feather disease virus infection. CLINICAL RELEVANCE: This report highlights the clinical impacts of BFDV in juvenile eastern rosellas that may result in their admission to wildlife care facilities, creating a biosecurity risk in institutions that may host other native parrots intended for release. The environmental stability of BFDV and resistance to disinfection requires strict quarantine procedures to prevent contamination and spread within a facility. It is recommended that high-risk species such as wild eastern rosella be excluded from facilities that may also house native parrots.


Journal of Avian Medicine and Surgery | 2013

Hematologic and Plasma Biochemical Reference Values for Three Species of Black Cockatoos (Calyptorhynchus species)

C. Holyoake; S. Vitali; K. Warren

Abstract: Black cockatoos in southwest Western Australia face population declines as a result of habitat loss and fragmentation, poaching, competition with other species, vehicle strikes, and shootings. In this study, hematologic and plasma biochemical reference values were determined for 3 endemic Western Australian black cockatoo species: Carnabys cockatoo (Calyptorhynchus latirostris) (n = 34), Baudins cockatoo (Calyptorhynchus baudinii) (n = 22), and forest red-tailed black cockatoo (Calyptorhynchus banksii naso) (n = 22). Significant sex-related differences were detected in Carnabys cockatoos, and differences were also found among the 3 species. The forest red-tailed black cockatoos showed a markedly greater eosinophil count than did the 2 white-tailed species. Blood values from samples obtained by different collection methods differed significantly for Carnabys cockatoos, which indicates that anesthesia may affect analyte values and that collection methods should remain consistent. The results of this study will be useful for clinically evaluating wild black cockatoos that are undergoing rehabilitation for release and will provide baseline data for future investigations of free-living black cockatoo health.


Australian Veterinary Journal | 2010

Preliminary investigation into the prevalence of mucormycosis in the platypus (Ornithorhynchus anatinus) in three catchments in north-west Tasmania

James Macgregor; C. Holyoake; Sarah Munks; I.D. Robertson; K. Warren

OBJECTIVE To investigate the distribution and prevalence of mucormycosis in platypus (Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania. PROCEDURE A field study was performed and resulted in the examination of 44 wild platypuses; in addition, one dead platypus and two live platypuses were examined after they were independently submitted to a local veterinary clinic. RESULTS No cases of mucormycosis were conclusively diagnosed. One platypus with signs consistent with those previously described in cases of mucormycosis was captured in the Emu River catchment. However, laboratory tests did not provide a definitive diagnosis for the lesion. Two platypuses from the Inglis catchment area had signs very similar to those previously described in cases of mucormycosis, but laboratory tests found Corynebacterium ulcerans to be the likely cause of the cutaneous ulcers on one of these platypuses and an unidentified fungal agent to be the cause of a cutaneous nodule in the other. CONCLUSIONS These findings do not prove that mucormycosis is absent from the populations studied. However, they may indicate that the prevalence of disease is low. The possibility that Mucor amphibiorum is present in a subclinical form in platypuses, or infecting another reservoir, is not excluded. The findings also suggest that caution should be exercised when diagnosing mucormycosis based on clinical findings alone and raise the possibility that some cases may have been incorrectly diagnosed.


Journal of Wildlife Diseases | 2015

PRESENTATION AND PROGNOSTIC INDICATORS FOR FREE-LIVING BLACK COCKATOOS (CALYPTORHYNCHUS SPP.) ADMITTED TO AN AUSTRALIAN ZOO VETERINARY HOSPITAL OVER 10 YEARS

C. Holyoake; S. Vitali; K. Warren

Abstract The veterinary records of three species of free-living, endangered black cockatoos (Calyptorhynchus spp.; n = 565) admitted to the Perth Zoo Veterinary Hospital in Western Australia during a 10-yr period (2000–09) were analyzed to determine the effect of clinical presentation and treatment on survival to release. The most-common reason for admission was trauma (at least 76.7% of cases), and trauma was also the most-frequent finding on necropsy examination (80.1% of cases). Anemia and paralysis-paresis were significant factors determining the decreased likelihood of survival of cockatoos undergoing rehabilitation. Human activities, in particular vehicle strike, were significant causes of morbidity and mortality in free-living black cockatoo populations.


Conservation Physiology | 2014

Investigation into the characteristics, triggers and mechanism of apnoea and bradycardia in the anaesthetized platypus (Ornithorhynchus anatinus)

James Macgregor; C. Holyoake; Patricia A. Fleming; I.D. Robertson; Joanne Connolly; K. Warren

By relating respiratory and heart rate changes observed in some platypuses under isoflurane anaesthesia to those produced by various stimuli to the trigeminal nerve we propose that in platypuses the changes that can result from isoflurane gas in the nasal cavity are most appropriately described by the term ‘nasopharyngeal response’.


Flacke, G., Becker, P., Cooper, D., Szykman Gunther, M., Robertson, I. <http://researchrepository.murdoch.edu.au/view/author/Robertson, Ian.html>, Holyoake, C. <http://researchrepository.murdoch.edu.au/view/author/Holyoake, Carlysle.html>, Donaldson, R. <http://researchrepository.murdoch.edu.au/view/author/Donaldson, Rebecca.html> and Warren, K. <http://researchrepository.murdoch.edu.au/view/author/Warren, Kristin.html> (2013) An infectious disease and mortality survey in a population of free-ranging African wild dogs and sympatric domestic dogs. International Journal of Biodiversity, 2013 . pp. 1-9. | 2013

An Infectious Disease and Mortality Survey in a Population of Free-Ranging African Wild Dogs and Sympatric Domestic Dogs

Gabriella L. Flacke; Penny A. Becker; D. Cooper; M. Szykman Gunther; I.D. Robertson; C. Holyoake; R. Donaldson; K. Warren

Disease can cause declines in wildlife populations and significantly threaten their survival. Recent expansion of human and domestic animal populations has made wildlife more susceptible to transmission of pathogens from domestic animal hosts. We conducted a pathogen surveillance and mortality survey for the population of African wild dogs (Lycaon pictus) in KwaZulu-Natal (KZN), South Africa, from January 2006–February 2007. Samples were obtained from 24 wild dogs for canine distemper virus (CDV) and canine parvovirus (CPV) serological testing. Data were collected on the presence of CDV, CPV, and rabies virus in the KZN domestic dog (Canis familiaris) population from 2004–06. The presence of these pathogens was confirmed in domestic dogs throughout KZN. Wild dogs exhibited 0% and 4.2% prevalence for CDV and CPV antibodies, respectively. In 2006 the largest wild dog pack in KZN was reduced from 26 individuals to a single animal; disease due to rabies virus was considered the most probable cause. This study provides evidence that CDV, CPV and rabies are potential threats to African wild dog conservation in KZN. The most economical and practical way to protect wild dogs from canine pathogens may be via vaccination of sympatric domestic dogs; however, such programmes are currently limited.


Infection, Genetics and Evolution | 2016

Molecular characterisation and genetic variation of Elephant Endotheliotropic Herpesvirus infection in captive young Asian elephants in Thailand

Supaphen Sripiboon; Bethany Jackson; William G.F. Ditcham; C. Holyoake; I.D. Robertson; Chatchote Thitaram; Pallop Tankaew; Preeda Letwatcharasarakul; K. Warren

Elephant Endotheliotropic Herpesvirus (EEHV) is emerging as a new threat for elephant conservation, since being identified as the cause of severe, often fatal, haemorrhagic disease in young Asian elephants. To describe positive cases and the molecular relatedness of virus detected in elephants in Thailand, we re-examined all available of EEHV samples occurring in young elephants in Thailand between 2006 and 2014 (n=24). Results indicated 75% (18/24) of suspected cases were positive for EEHV by semi-nested PCR. Further gene analysis identified these positive cases as EEHV1A (72%, 13/18 cases), EEHV1B (11%, 2/18) and EEHV4 (17%, 3/18). This study is the first to phylogenetically analyse and provide an overview of most of the known EEHV cases that have occurred in Thailand. Positive individuals ranged in age from one to nine years, with no sex association detected, and occurred across geographical locations throughout the country. All individuals, except one, were captive-born. No history of direct contact among the cases was recorded, and this together with the fact that various subtype clusters of virus were found, implied that none of the positive cases were epidemiologically related. These results concur with the hypothesis that EEHV1 is likely to be an ancient endogenous pathogen in Asian elephants. It is recommended that active surveillance and routine monitoring for EEHV should be undertaken in all elephant range countries, to gain a better understanding of the epidemiology, transmission and prevention of this disease.


Journal of Wildlife Diseases | 2017

Investigation into individual health and exposure to infectious agents of platypuses (Ornithorhynchus anatinus) in two river catchments in northwest Tasmania

James Macgregor; C. Holyoake; Sarah Munks; Joanne Connolly; I.D. Robertson; Patricia A. Fleming; K. Warren

Abstract Changes in the health of individuals within wildlife populations can be a cause or effect of population declines in wildlife species. Aspects of individual platypus (Ornithorhynchus anatinus) health have been reported. However, holistic studies investigating potential synergistic effects of both pathogens and environmental factors are needed to expand understanding of platypus individual health. We collected baseline data on the health of platypuses in two Tasmanian river catchments (including evidence of the potentially fatal fungal disease mucormycosis) and on individual, demographic, and geographic patterns associated with health data results. We examined 130 wild platypuses from the Inglis River Catchment and 24 platypuses from the Seabrook Creek Catchment in northwest Tasmania between 29 August 2011 and 31 August 2013. More than 90% of captured platypuses were infected with ticks, Theileria spp., and trypanosomes. Evidence of exposure to other infections, including Salmonella spp., Leptospira spp., and intestinal parasites, was low (<10%). Three platypuses had single fungal granulomas in the webbing of a forefoot, but no evidence of mucormycosis was found in any of the study animals. Possible subclinical hepatopathies or cholangiohepatopathies were found in six platypuses. Exposure to infectious agents did not cluster geographically, demographically, or in individuals, and there was minimal evidence of morbidity resulting from infection. This study has provided important baseline data for monitoring the effects of threatening processes, including mucormycosis, on the health of infected populations.

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Arvind Varsani

Arizona State University

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