SARCOPTIC MANGE IN THE COMMON , VOMBATUS URSINUS (SHAW, 1800)

Lee Francis Skerratt

Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy

June 2001

Department of Veterinary Science

The University of ii

“The extravagant and fantastic nature of wild species, and their undisciplined response to various procedures create unique problems for those interested in disease”

Gary A. Wobeser

To those who helped me with this study.

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ABSTRACT

Sarcoptic mange affects the (Vombatus ursinus) throughout its range. Prevalence of the disease is generally low, with less than 5% of in a population affected. However, epizootics occur sporadically. Sarcoptic mange is less prevalent in southern hairy-nosed wombats (Lasiorhinus latifrons) but may be widespread. Sarcoptic mange has not been reported in the sole remaining population of northern hairy-nosed wombats (Lasiorhinus krefftii) at Epping Forest, Queensland.

Whilst mange epizootics are sporadic, they have the potential to threaten the survival of small, remnant populations of wombats.

Studies of free-living common wombats with severe sarcoptic mange showed that the anterolateral surface was most heavily parasitised followed by the posterolateral surface, the dorsal region between the ears, the ears, ventral abdomen, medial aspect of the legs, axillary and inguinal areas, and the dorsal midline. Larvae were the most prevalent life-cycle stage followed by eggs, nymphs, females, and males. A stage structured population model showed that the nymphal stages had the lowest survivorship followed by the larval stage. The number of mites and the severity of clinical signs, namely thickness of scale crust and the degree of alopecia, were correlated and were symmetrical on each side of the body. Fissuring of crust and skin only occurred when scale crust was present. Severe sarcoptic mange causes emaciation, anaemia and starvation in wombats eventually leading to death. It also predisposed wombats to bacterial infection of internal organs.

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In captive common wombats experimentally infected with S. scabiei var. wombati, four of five wombats infected for the first time with 5000 mites on their right shoulders developed severe parakeratotic sarcoptic mange within 11 weeks after infection. Two wombats given 1000 mites developed mild parakeratotic sarcoptic mange or did not develop mange 11 weeks after infection. Mange was less severe in a single wombat reinfected with mites. Initial signs of mange were erythema followed by parakeratosis, alopecia, excoriation and fissuring of parakeratotic crust and skin.

Erythema usually became apparent within 14 days after infection or within 24 hrs of reinfection. Alopecia first occurred between 35 and 77 days after infection. Clinical signs increased in severity over time and lesions spread slowly from the site of inoculation. Mangy wombats scratched excessively, lost weight and exhibited a significant neutrophilia compared with control wombats. Treatment of mange with three injections of ivermectin, 300 µg/kg, 10 days apart led to complete resolution of clinical signs. However mites were not entirely eliminated until wombats received a second course of 3 treatments.

In free-living common wombats experimentally infected with S. scabiei var. wombati, three wombats infected with 6000 to 8000 mites on their lateral surfaces developed mild sarcoptic mange within 14 weeks after infection. Two wombats infected with 4000 and 8000 mites, respectively on lateral surfaces developed moderate sarcoptic mange within 14 weeks after infection. Free-living common wombats, experimentally infected with S. scabiei, travelled significantly further and used a larger area at night than wombats without mange. They were also less likely to use a different burrow to the one that they used the previous day for diurnal shelter or

v to investigate and enter burrows during their nocturnal activities other than the burrow used for diurnal shelter.

The cellular immune response in the dermis of wombats with sarcoptic mange exhibited some typical aspects of an immune response to S. scabiei. There was an induction phase for wombats experimentally infected with S. scabiei represented by the absence of a dermal inflammatory infiltrate for at least 12 days after infection. T- lymphocytes, plasma cells, mast cells and neutrophils then entered the dermis, which is consistent with the features of a delayed hypersensitivity response. In free-living common wombats with severe sarcoptic mange, T-lymphocytes, mast cells, neutrophils and eosinophils were present in their dermis suggesting that an immediate hypersensitivity response and immune tolerance may develop after a delayed hypersensitivity response.

The mitochondrial small subunit 12S ribosomal RNA gene was sequenced for

23 S. scabiei originating from 8 wombats, 1 dog and 3 humans. For mites from all 3 hosts, 9 distinct 12S sequences occurred, differing from one another by 1-8 nucleotides over a sequence length of 326 base pairs, with a total of 12 variable nucleotide positions. There were no fixed genetic differences between S. scabiei from different hosts or localities nor was there significant phylogenetic divergence among mites from different hosts or localities.

Free-living wombats living at a density of approximately 19 wombats per hectare in a strip of remnant riparian vegetation along the Yea River at Padilpa,

Victoria, frequently shared burrows and their home ranges overlapped. Sarcoptes

vi scabiei was not found nor were there signs of sarcoptic mange in the population.

Introduction of 34,000 S. scabiei var. wombati onto five adult wombats, which developed mild to moderate sarcoptic mange, did not result in any apparent spread of infection to other wombats within the population 18 weeks after introduction.

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DECLARATION

This is to certify that

(i) the thesis comprises my original work, except where indicated in the preface

(ii) due acknowledgment has been made in the text to all other material used,

(iii) the thesis is less than 100,000 words in length, exclusive of tables, maps, bibliographies and appendices.

Lee Skerratt

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PREFACE

Roger Martin and Kath Handasyde instigated the survey of mange in wombats and were predominantly involved in the distribution of the questionnaire, analysis of returns and presentation of the survey results in chapter two. Clive Berger wrote the matrix model, which describes the population dynamics of S. scabiei in chapter six.

Shelley Walton sequenced the third domain of the mitochondrial small subunit 12S ribosomal RNA gene from seven of the haplotypes of S. scabiei described in chapter seven. These have also been published in her PhD thesis.

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ACKNOWLEDGMENTS

There were many people who assisted with the work described herein and I sincerely thank them. Ian Beveridge and Deborah Middleton provided excellent supervision and support for this study. Roger Martin and Kath Handasyde supervised my plunge into the realm of field-work and displayed tremendous interest in the topic.

Nick Campbell supervised my foray into molecular biology. My father John Skerratt became my field assistant when he retired from work in the last year of the project and my mother Marilyn Skerratt did a wonderful job of catering for field trips. My partner Lee Berger helped when things got desperate and provided a shoulder to cry on when she could not. Clive Berger helped me to understand some of the basic principles of population modelling. Sam Banks and Melissa Twaddell, two of the few people mad enough to also work on wombats, were a great help on field trips. Ian

Skerratt, Derek Harms, Kate Steinmann, Danny Reddan, Les Steinmann and students from the University of Melbourne and Monash University also helped with field-work and Kate along with Marli Middleton translated several French articles relevant to sarcoptic mange in wombats. Trish Becheras is thanked for her support and for allowing me to study wombats on her property. Malcolm White is also thanked for allowing me to follow wombats onto his property.

Christine Andersen helped with handling and sample collection from captive wombats and John Bryant cared for captive wombats. Josie Wilson cut and stained histological sections. Debra Presidente and Tania Smith conducted clinical pathological work. Jim Phelan, Peter Holz and Janine Ferguson along with staff of

Healesville Sanctuary, Bill Shenfield, Jaan Enden, Jenny McAuliffe, Janey Jackson,

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Rebecca Wilcox, Reg Withers, Martina Booker and staff of Kinglake National Park helped collect mangy wombats. Janey Jackson also identified ticks. Judy Robertson at

Murdoch University performed electrophoretograms and Brian Rich helped with their interpretation. Garry Anderson provided statistical advice and Phillip Clark and Bruce

Parry provided advice on clinical pathology. Robin Gasser helped with the analysis of molecular data. The Mackinnon Project provided a trailer for field trips. Peter

Mitchell, Clive Marks and Barbara Triggs reviewed an early version of the questionnaire survey. Barbara Triggs and Barbara St John assisted with the distribution of the questionnaire survey in NSW and SA. Steve Barker gave me an opportunity to conduct molecular research and work at another institute, The

University of Queensland.

Finally I thank my colleagues at work for their support, Xingquan Zhu,

Charles Gauci and Rick Rolfe with whom I shared an office, post graduate students,

Guo-Chiuan Hung, David Woollard, Itaru Sato, Conan Chow, Jane Conole and

Jennifer Monkhouse and parasitologists Neil Chilton, Marshall Lightowlers and

Amanda Colebrook.

Lee Skerratt was supported by an Australian Postgraduate Award. This project was funded by the Holsworth Wildlife Research Fund, $12,000 over three years. The

South Australian Conservation Trust provided funding to carry out the survey, $1000.

This research was conducted with approval from the Veterinary Science

Animal Experimentation Ethics Sub-Committee, register numbers 97082 and 98108 and permission from the Department of Natural Resources and Environment, permit

xi numbers RP-97-046, RP-97-138, 10000433, 10000434, 10000936, 10000988 and

10001318. Antibodies for immunohistochemistry generously donated by the LRF

Immunodiagnostics Unit, Department of Clinical Biochemistry and Cellular Science,

University of Oxford, United Kingdom were imported with the permission of the

Australian Quarantine and Inspection Service, permit number 199905742.

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TABLE OF CONTENTS Page No.

ABSTRACT...... III

DECLARATION ...... VII

PREFACE ...... VIII

ACKNOWLEDGMENTS...... IX

TABLE OF CONTENTS...... XII

LIST OF PUBLICATIONS ...... XV

LIST OF TABLES ...... XX

LIST OF FIGURES...... XXIII

CHAPTER 1. INTRODUCTION AND LITERATURE REVIEW

1.1. INTRODUCTION...... 29 1.2. LITERATURE REVIEW...... 30 1.2.1. SARCOPTIC MANGE IN WOMBATS...... 30 1.2.2. BIOLOGY OF SARCOPTES SCABIEI...... 35 1.2.3. BIOLOGY OF THE COMMON WOMBAT ...... 41 1.3. CONCLUSIONS...... 45 1.4. RESEARCH APPROACH...... 46

CHAPTER 2. CURRENT DISTRIBUTION OF SARCOPTIC MANGE IN WOMBATS

2.1. INTRODUCTION...... 50 2.2. MATERIALS AND METHODS...... 50 2.3. RESULTS...... 51 2.4. DISCUSSION ...... 53

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CHAPTER 3. DISTRIBUTION OF LIFE CYCLE STAGES OF SARCOPTES SCABIEI VAR.WOMBATI AND CLINICOPATHOLOGICAL EFFECTS OF SEVERE MANGE ON COMMON WOMBATS (VOMBATUS URSINUS) IN

3.1. INTRODUCTION...... 62 3.2. MATERIALS AND METHODS...... 63 3.3. RESULTS...... 67 3.4. DISCUSSION ...... 73

CHAPTER 4. EXPERIMENTAL INFECTION OF CAPTIVE COMMON WOMBATS (VOMBATUS URSINUS) WITH SARCOPTES SCABIEI VAR. WOMBATI

4.1. INTRODUCTION...... 88 4.2. MATERIALS AND METHODS...... 89 4.3. RESULTS...... 93 4.4. DISCUSSION ...... 99

CHAPTER 5. INFLAMMATORY RESPONSE IN THE DERMIS OF COMMON WOMBATS (VOMBATUS URSINUS) INFECTED WITH SARCOPTES SCABIEI VAR. WOMBATI

5.1. INTRODUCTION...... 120 5.2. MATERIALS AND METHODS...... 121 5.3. RESULTS...... 125 5.4. DISCUSSION ...... 128

CHAPTER 6. POPULATION DYNAMICS OF SARCOPTES SCABIEI VAR. WOMBATI

6.1. INTRODUCTION...... 137 6.2. MATERIALS, METHODS AND RESULTS...... 137 6.3. DISCUSSION ...... 143

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CHAPTER 7. VARIATION IN THE MITOCHONDRIAL SMALL SUBUNIT 12S RIBOSOMAL RNA GENE OF SARCOPTES SCABIEI FROM WOMBAT, DOG AND HUMAN

7.1. INTRODUCTION...... 150 7.2. MATERIALS AND METHODS...... 151 7.3. RESULTS...... 153 7.4. DISCUSSION ...... 156

CHAPTER 8. THE EFFECTS OF SARCOPTIC MANGE ON BEHAVIOUR AND ECOLOGY OF COMMON WOMBATS IN A POPULATION AT HIGH DENSITY

8.1. INTRODUCTION...... 161 8.2. MATERIALS AND METHODS...... 162 8.3. RESULTS...... 173 8.4. DISCUSSION ...... 185

CHAPTER 9. PRACTICAL IMPLICATIONS OF THIS STUDY IN RELATION TO THE MANAGEMENT OF SARCOPTIC MANGE IN WOMBAT POPULATIONS ...... 246

BIBLIOGRAPHY ...... 259

APPENDICES...... 284

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LIST OF PUBLICATIONS

Journal Articles

Skerratt, L. F., Martin, R. W., and K. Handasyde. 1998. Sarcoptic mange in wombats.

Australian Veterinary Journal 76: 1-3.

Martin, R. W., Handasyde, K., and L. F. Skerratt. 1998. Current distribution of

sarcoptic mange in wombats. Australian Veterinary Journal 76: 4-7.

Skerratt, L. F., Middleton, D., and I. Beveridge. 1999. Distribution of life cycle stages

of Sarcoptes scabiei var.wombati and effects of severe mange on common

wombats in Victoria. Journal of Wildlife Diseases 35: 633-646.

Skerratt, L. F., and I. Beveridge. 1999. Human scabies of wombat origin. Australian

Veterinary Journal 77: 23.

Skerratt, L. F. 2001. Clinical response of captive common wombats Vombatus ursinus

to infection with Sarcoptes scabiei var. wombati. Journal of Wildlife Diseases

submitted.

Skerratt, L. F. 2001. Inflammatory response of captive common wombats Vombatus

ursinus to infection with Sarcoptes scabiei var. wombati. Journal of Wildlife

Diseases submitted.

Skerratt, L. F., Campbell, N., Walton, S., Kemp, D. and S. Barker. 2001. Genetic

variation at the mitochondrial 12S locus among populations of Sarcoptes scabiei

originating from wombat, dog and human. In preparation.

Skerratt, L. F., Skerratt, J. H. L., Banks, S., Martin, R. W., and K. Handasyde. 2001.

Aspects of the ecology of common wombats Vombatus ursinus at high density in

agricultural land. In preparation.

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Skerratt, L. F., Skerratt, J. H. L., Martin, R. W., and K. Handasyde. 2001. The effects

of sarcoptic mange on the behaviour of wild common wombats Vombatus

ursinus. In preparation.

Conference Abstracts

Martin, R., Handasyde, K., and L. F. Skerratt. 1997. Mange in wombats. In: The

Proceedings of the Annual Conference of the Wildlife Disease Association,

Australasian Section, October 1997, Flinders Island, Tasmania.

Skerratt, L. F. 1998. Parasitology of Sarcoptes scabiei var.wombati and debilitating

effects of severe sarcoptic mange on common wombats Vombatus ursinus. In:

Proceedings of the Annual Conference of the Wildlife Disease Association,

Australasian Section, July 1998, Calperum Station, Bookmark Biosphere,

South Australia.

Skerratt, L. F. 1998. Parasitology of Sarcoptes scabiei var.wombati and debilitating

effects of severe sarcoptic mange on common wombats Vombatus ursinus. In:

Proceedings of the Annual Conference of the Australian Society for

Parasitology, October 1998, Latrobe University, Victoria.

Skerratt, L. F. 1999. Experimental infection of common wombats Vombatus ursinus

with Sarcoptes scabiei var. wombati. In: Proceedings of the Annual

Conference of the Wildlife Disease Association, Australasian Section, July

1999, Canberra University Field Station, Jervis Bay, New South Wales.

Skerratt, L. F. 1999. Experimental infection of common wombats Vombatus ursinus

with Sarcoptes scabiei var. wombati. In: Proceedings of the Annual

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Conference of the Australian Society for Parasitology, September 1999,

Yeppoon, Queensland.

Skerratt, L. F. 2000. Immunological and behavioural response of common wombats

Vombatus ursinus to Sarcoptes scabiei var. wombati infection. In: Proceedings

of the Joint Annual Conferences of the Wildlife Disease Association,

Australasian Section and Wildlife Society of the New Zealand Veterinary

Association, December 2000, Auckland University Marine Biology Field

Centre, Leigh, New Zealand.

Skerratt, L. F. 2001. The management of sarcoptic mange in wombat populations. In:

Veterinary Conservation Biology: Wildlife Health and Management in

Australasia, July 2001 Taronga Zoo, Sydney, New South Wales, Australia.

Conference Posters

Skerratt, L. F. 1998. Sarcoptic mange in wombats. In: The 11th Annual Conference of

the Australasian Wildlife Management Society, November 1998, University of

Queensland, Gatton College, Queensland.

Internet Articles

Skerratt, L. F. 1998. Sarcoptic mange in wombats.

http://www.wha.org.au/pages/resear02.html

Other Presentations

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Skerratt, L. F. 2000. Sarcoptic mange in the common wombat Vombatus ursinus.

Presented within the Faculty of Veterinary Science, University of Melbourne,

November 29, 2000. PhD Graduation Seminar.

Skerratt, L. F. 1998. Sarcoptic mange in the common wombat Vombatus ursinus.

Presented within the Faculty of Veterinary Science, University of Melbourne,

April 22, 1998. PhD Confirmation Seminar.

Skerratt, L. F. 1999. Sarcoptic mange in wombats. Presented to the Wildlife

Appreciation Group within the Department of Veterinary Science, University

of Melbourne. Melbourne Zoological Gardens, August 16, 1999.

Newsletters

Skerratt, L. F. 1999. Sarcoptic mange in the common wombat. Australian Wildlife

Management Society Newsletter, November 1999, 12: 7.

Media publications

Griffiths, K. A. 1998. Wombat mange alert. In: Sunday Herald Sun, July 21, 1998.

Barnes, C. 1998. Save our wombats. In: The Australian Women’s Weekly. October

1998.

The Totally Wild Team. 1999. Mange in wombats. On “Totally Wild” Channel 10,

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July 27, 1999.

Collaborative Articles

Walton, S., Low Choy, J., Bonson, A., Vale, A., McBroom, J., Taplin, D., Arlian, L.,

Mathews, J. D., Currie, B. and D. J. Kemp. 1999. Genetically distinct dog-

derived and human-derived Sarcoptes scabiei in scabies-endemic

communities in northern Australia. American Journal of Tropical Medicine

and Hygiene 61: 542-547.

Zahler, M., Essig, A., Gothe, R. and H. Rinder. 1999. Molecular analyses suggest

monospecificity of the genus Sarcoptes (Acari: Sarcoptidae). International

Journal of Parasitology 29: 759-766.

Banks, S.C., Skerratt, L.F. and A.C. Taylor. 2001. Female dispersal and relatedness

structure in common wombats Vombatus ursinus. Journal of Zoology

(London) in press.

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LIST OF TABLES Page No.

Table 2.1. Number of localities at which clinical signs of mange were observed and Sarcoptes scabiei var. wombati was present on common wombats...... 57 Table 2.2. Prevalence of clinical signs of mange and presence of Sarcoptes scabiei var. wombati on common wombats during a three month period (November 1995 to January 1996)...... 58 Table 2.3. Presence of clinical signs of mange in southern hairy-nosed wombats at various localities in South Australia...... 59 Table 3.1. Mean numbers of Sarcoptes scabiei var. wombati per square centimetre at 35 sites on 10 wombats with severe parakeratotic sarcoptic mange from Victoria, Australia...... 81 Table 3.2. Percentage of wombats (n = 10) from Victoria, Australia with crust, alopecia and fissuring at 35 sites on the body...... 82 Table 3.3. Haematological values for healthy captive wombats together with those of Presidente (1982), compared with wombats exhibiting severe parakeratotic sarcoptic mange...... 83 Table 3.4. Biochemical values for healthy captive wombats together with those of Presidente (1982), compared with wombats exhibiting severe parakeratotic sarcoptic mange...... 84 Table 3.5. Numbers of mangy wombats with elevated glutamate dehydrogenase concentrations, reactive hepatitis and fatty change in the liver...... 85 Table 4.1. Temporal development of clinical signs of sarcoptic mange in common wombats infected and reinfected with 1000 and 5000 mites...... 106 Table 4.2. Number of mites/cm2 and thickness of scale crust on shoulders, percentage of time spent scratching determined by 10 minute observation and change in concentration of circulating neutrophils for wombats at 46 and 77 days after infection with 1000 or 5000 mites on their shoulders...... 107 Table 5.1. Type, source, specificity and dilution of primary antibodies used in immunohistochemical staining of wombat tissues and whether antibodies differentially stained cells...... 132

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Table 5.2. Mean numbers of mites and types of cells in the upper dermis of naturally infected free-living wombats with sarcoptic mange at sites Nos. 7-12 in Fig. 3.1 compared with normal wombats...... 133 Table 5.3. Numbers of various cell types per mm2 in the upper dermis and thickness of the epidermis (µm) in wombats experimentally infected with Sarcoptes scabiei var. wombati and in control wombats on days 0 and 77 after infection.134 Table 7.1. Variable sites in the coding region of the mitochondrial 12S rRNA gene of Sarcoptes scabiei...... 158 Table 8.1. Number of trap nights, number of wombats caught and the proportion of wombats caught on consecutive trap nights in this study at Padilpa, Victoria, compared with those of McIlroy (1976) at Buccleuch State Forest, New South Wales...... 202 Table 8.2. Age and sex of the common wombats (Vombatus ursinus) trapped at Padilpa, Victoria, in 1999/2000...... 203 Table. 8.3. Weight, head length, body length, length of manus and pes, length and width of testis and epididymis, age and sex classes of wombats (Vombatus ursinus) trapped at Padilpa, Victoria, from August 1999 to November 2000 ...204 Table 8.4. Number of common wombats (Vombatus ursinus), study area, density of wombats and climate* at various locations in south-eastern Australia...... 205 Table 8.5. Numbers of burrows at Padilpa, Victoria that contained no wombats, one wombat or multiple wombats.*...... 206 Table 8.6. Age, sex and reproductive status of common wombats (Vombatus ursinus) occupying the same burrow at Padilpa, Victoria...... 207 Table 8.7. Number of times that a common wombat (Vombatus ursinus) was radio located in a burrow, number of different burrows used by a wombat and the range of the number of times that a wombat was radio located in each burrow at Padilpa, Victoria, from August 1999 to November 2000...... 208 Table 8.8. Precipitation (mm) at Glenburn (37°22'53"S, 145°28'20"E), elevation 250 m, and average maximum air temperatures (°C) at Eildon Fire Tower (37°12'39"S, 145°50'27"E), elevation 638 m, for each month from August 1999 to November 2000...... 209 Table 8.9. Mean distance travelled and area used per night by common wombats (Vombatus ursinus) affected or not affected by sarcoptic mange at Padilpa, Victoria, in 2000...... 210

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Table 8.10. Distances travelled and the total area used per night for male and female common wombats (Vombatus ursinus) at Padilpa, Victoria, in 2000...... 211 Table 8.11. Time of emergence from a burrow for common wombats (Vombatus ursinus) at Padilpa, Victoria, during the summer of 1999/2000...... 212 Table 8.12. Prevalence of ectoparasites on common wombats at Padilpa, Victoria, compared with other sites in Victoria: Morwell, Gippsland (Smales, 1982) and Healesville (Skerratt, 1998), as well as Buccleuch State Forest, New South Wales (McIlroy, 1973)...... 213 Table 8.13. Numbers of Sarcoptes scabiei var. wombati used to infect common wombats (Vombatus ursinus) at Padilpa, Victoria, and the intensity of infection on the shoulders of infected wombats 50 and 100 days after infection and 28 days after treatment with an acaricide, ivermectin...... 214 Table 8.14. Average severity of clinical signs of sarcoptic mange, parakeratosis (scale crust), hair loss and erythema in common wombats (Vombatus ursinus) at Padilpa, Victoria, infected with Sarcoptes scabiei var. wombati before and after treatment...... 215 Table 8.15. Change in weight of common wombats (Vombatus ursinus) prior to infection with Sarcoptes scabiei var. wombati, after infection and after treatment with ivermectin at 400-800 µg/kg at Padilpa, Victoria...... 216 Table 8.16. Ratio of the number of nights a common wombat (Vombatus ursinus) was located versus the number of different burrows used and the ratio of the number of consecutive nights a wombat was located versus the number of times the wombat changed burrows at Padilpa, Victoria...... 217 Table 8.17. Location in body and persistence of radio transmitters in common wombats (Vombatus ursinus) at Padilpa, Victoria, and extent of acceptance or rejection by wombats...... 218

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LIST OF FIGURES Page No.

Figure 1.1. Scanning electron micrograph of an adult female, Sarcoptes scabiei var. wombati (length of body 468 µm)...... 48 Figure 1.2. Common wombat (Vombatus ursinus) with severe sarcoptic mange above ground at noon in the Wombat State Forest, Bullengarook, Victoria in 1998.....48 Figure 1.3. Distribution of extant wombats, the common wombat (CW) (Vombatus ursinus), the southern hairy-nosed wombat (SHW) (Lasiorhinus latifrons) and the northern hairy-nosed wombat (NHW) (Lasiorhinus krefftii) (Strahan, 1995)...... 49 Figure 2.1. Occurrence of mange in relation to the current distribution of the common wombat (Vombatus ursinus)...... 60 Figure 2.2. Occurrence of mange in relation to the current distribution of the southern hairy-nosed wombat (Lasiorhinus latifrons)...... 61 Figure 3.1. Mean densities of mites, S. scabiei var. wombati, in 10 wombats with severe parakeratotic sarcoptic mange, at sites on lateral surfaces, along the dorsal midline and on the ventral surface of the body...... 86 Figure 3.2. Adult, male common wombat (Vombatus ursinus), from Christmas Hills, Victoria with severe parakeratotic sarcoptic mange showing typical distribution of parakeratotic scale, hair loss and excoriation...... 87 Figure 3.3. Adult, male common wombat (Vombatus ursinus), from Christmas Hills, Victoria with severe parakeratotic sarcoptic mange showing parakeratotic scale adherent to the skin...... 87 Figure 4.1 Schematic representation of experimental infection of common wombats, Vombatus ursinus, with the mange mite, Sarcoptes scabiei var. wombati...... 110 Figure 4.2 Mean concentration of neutrophils in control wombats and mange affected wombats at 0, 19, 34 and 77 days after infection with S. scabiei var. wombati.111 Figure 4.3. Adult, female, captive common wombat (Vombatus ursinus) (Infected 2) with sarcoptic mange, 77 days after infection of her left shoulder with 1000 Sarcoptes scabiei var. wombati...... 112

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Figure 4.4. Adult, female, captive common wombat (Vombatus ursinus) (Infected 2) with parakeratotic scale, hair loss, erythema and excoriation on the left shoulder, 77 days after infection with 1000 Sarcoptes scabiei var. wombati...... 112 Figure 4.5. Adult, female, captive common wombat (Vombatus ursinus) (Infected 3) with sarcoptic mange, 77 days after infection of her right shoulder with 5000 Sarcoptes scabiei var. wombati...... 113 Figure 4.6. Adult, female, captive common wombat (Vombatus ursinus) (Infected 3) with parakeratotic scale crust, hair loss, fissuring and excoriation on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati. ...113 Figure 4.7. Adult, female, captive common wombat (Vombatus ursinus) (Infected 4) with sarcoptic mange, 77 days after infection of her right shoulder with 5000 Sarcoptes scabiei var. wombati...... 114 Figure 4.8. Adult, female, captive common wombat (Vombatus ursinus) (Infected 4) with parakeratotic scale crust, hair loss and fissuring on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati...... 114 Figure 4.9. Adult, female, captive common wombat (Vombatus ursinus) (Infected 5) with sarcoptic mange, 77 days after infection of her right shoulder with 5000 Sarcoptes scabiei var. wombati...... 115 Figure 4.10. Adult, female, captive common wombat (Vombatus ursinus) (Infected 5) with parakeratotic scale and hair loss on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati...... 115 Figure 4.11. Adult, male, captive common wombat (Vombatus ursinus) (Infected 6) with sarcoptic mange, 77 days after infection of his right shoulder with 5000 Sarcoptes scabiei var. wombati...... 116 Figure 4.12. Adult, male, captive common wombat (Vombatus ursinus) (Infected 6) with parakeratotic scale crust, hair loss and fissuring on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati...... 116 Figure 4.13. Adult, male, captive common wombat (Vombatus ursinus) (Reinfected 1) with sarcoptic mange, 77 days after infection of his right shoulder with 5000 Sarcoptes scabiei var. wombati...... 117 Figure 4.14. Adult, male, captive common wombat (Vombatus ursinus) (Reinfected 1) with parakeratotic scale crust, hair loss and fissuring on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati...... 117

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Figure 4.15. Adult, female, captive common wombat (Vombatus ursinus) (Reinfected 2) with sarcoptic mange, 77 days after infection of her right shoulder with 5000 Sarcoptes scabiei var. wombati...... 118 Figure 4.16. Adult, female, captive common wombat (Vombatus ursinus) (Reinfected 2) with parakeratotic scale and hair loss on the right shoulder, 77 days after infection with 5000 Sarcoptes scabiei var. wombati...... 118 Figure 4.17. Adult, female, captive common wombat (Vombatus ursinus) (Infected 7) with sarcoptic mange, 41 days after infection of her right shoulder with 5000 Sarcoptes scabiei var. wombati. The fur was clipped so that parakeratotic scale was visible...... 119 Figure 4.18. Adult, female, captive common wombat (Vombatus ursinus) (Infected 3) 44 days after treatment for severe sarcoptic mange with three consecutive injections of ivermectin at 300 µg/kg...... 119 Figure 5.1. Changes in the percentage of cell types in the cellular infiltrate, which occurred in the upper dermis of wombats experimentally infected with Sarcoptes scabiei var. wombati, 77 days after infection...... 135 Figure 5.2. Change in epidermal thickness (µm) with time in wombats (n=7) experimentally infected with 1000 to 5000 Sarcoptes scabiei var. wombati.....136 Figure. 6.1. Constrained regressions of the life-cycle stages of Sarcoptes scabiei var. wombati...... 146 Figure 6.2. Population trajectory for density of Sarcoptes scabiei on wombats when 6 larvae, 2 nymphs and a female occurred per cm2 on 0 days after infection and λ=1.2 for a 2 day time interval...... 147 Figure 6.3. Population trajectory for density of Sarcoptes scabiei on wombats when 6 larvae, 2 nymphs and a female occurred per cm2 on 0 days after infection and λ=1.1 for a 2 day time interval...... 148 Figure 6.4. Population trajectory for density of Sarcoptes scabiei on wombats when 6 larvae, 2 nymphs and a female occurred per cm2 on 0 days after infection and λ=1.35 for a 2 day time interval...... 149 Figure 7.1. One of 10 maximum parsimony trees of relationships among the 9 distinct 12S haplotypes (haplo) from Sarcoptes scabiei presented as an unrooted network...... 159

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Figure 7.2. Consensus nucleotide sequence data for a fragment (326 bp) of the coding region of the mitochondrial 12S rRNA gene of Sarcoptes scabiei obtained from 23 mites...... 160 Figure 8.1. Field site at Padilpa, Victoria, in spring 2000 showing strip of riparian vegetation and adjacent pasture...... 220 Figure 8.2. Adult, male common wombat (Vombatus ursinus) (Male 2) sitting near burrow entrance during the day at Padilpa, Victoria...... 220 Figure 8.3. Escape tunnel, dug around trap which was placed over the entrance to the burrow at Padilpa, Victoria...... 221 Figure 8.4. Damaged trap caused by a common wombat (Vombatus ursinus) that escaped by breaking the welds of the iron mesh and pushing the swinging gate past the angle iron that was designed to stop the gate swinging out...... 221 Figure 8.5. Joey, female common wombat (Vombatus ursinus), in trap at Padilpa, Victoria...... 222 Figure 8.6. Earliest stage of development of a joey (Vombatus ursinus) seen at Padilpa, Victoria, in 2000...... 222 Figures 8.7. Engorged adult female ticks, Aponomma auruginans, on the inner thigh of a common wombat (Vombatus ursinus) at Padilpa, Victoria, in 2000...... 223 Figure 8.8. Adult, male common wombat (Vombatus ursinus) with a torn cloaca and bite wounds at Padilpa, Victoria, in 2000...... 223 Figures 8.9. Surgical wound that enabled implantation of a radio transmitter in the ventral neck region of an adult, male common wombat (Vombatus ursinus) (Male 2)...... 224 Figure 8.10. Bulge in ventral neck region due to a subcutaneous radio transmitter and surgical wound created during implantation, closed with simple interrupted stiches of nylon suture material in an adult, male common wombat (Vombatus ursinus) (Male 2)...... 224 Figures 8.11. Radio transmitter glued to a circular ear tag in the right ear of an adult, female common wombat (Vombatus ursinus) (Female 2)...... 225 Figure 8.12. Hole, 3 m deep, created when digging with a shovel to recover a radio transmitter lost in a wombat burrow 14 m from its entrance at Padilpa, Victoria...... 226 Figure 8.13. Back hoe used to recover radio transmitters from wombat burrows at Padilpa, Victoria...... 226

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Figure 8.14. Spool containing cotton bobbins stuck with epoxy resin to the fur of an adult, male common wombat (Vombatus ursinus) (Male 1)...... 227 Figure 8.15. Thread line distributed by a common wombat (Vombatus ursinus) with a spool glued to its fur...... 227 Figure 8.16. Scratchings and scats used by common wombats (Vombatus ursinus) to mark territory at Padilpa, Victoria...... 228 Figure 8.17. Body surface of wombats, divided into 13 sections in order to quantify the extent of sarcoptic mange in wombats...... 229 Figure 8.18. Number of common wombats (Vombatus ursinus) captured along the Yea River at Padilpa, Victoria, compared with the number of wombats caught the first night a trap was placed over a burrow...... 230 Figure 8.19. Number of common wombats (Vombatus ursinus) that were captured along the Yea River at Padilpa, Victoria, versus the number of wombats known to exist in the population...... 231 Figure 8.20. Weight (kg) of pouch young of common wombats (Vombatus ursinus) trapped at Padilpa, Victoria, from August 1999 to November 2000...... 232 Figure 8.21. Weight (kg) versus head length (mm) for adult male and female common wombats (Vombatus ursinus) trapped at Padilpa, Victoria, from August 1999 to November 2000...... 233 Figure 8.22. Growth of joeys (kg) (Vombatus ursinus) trapped at Padilpa, Victoria, from August 1999 to November 2000...... 234 Figure 8.23. Map of field site at Padilpa, Victoria, showing location of common wombat (Vombatus ursinus) burrows along the Yea River...... 235 Figure 8.24. Map of field site at Padilpa, Victoria, showing area used by three adult male common wombats (Vombatus ursinus)...... 236 Figure 8.25. The number of times that the location of common wombats (Vombatus ursinus) was determined (fixes) compared with the total area used by wombats at Padilpa, Victoria, between December 1999 and November 2000...... 237 Figure 8.26. Map of field site at Padilpa, Victoria showing area used by two adult female common wombats (Vombatus ursinus)...... 238 Figure 8.27. Map of field site at Padilpa, Victoria showing area used by an adult female common wombat (Vombatus ursinus)...... 239 Figure 8.28. Map of field site at Padilpa, Victoria showing area used by an adult female and sub-adult male common wombat (Vombatus ursinus)...... 240

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Figure 8.29. Anaesthetised adult, male common wombat (Vombatus ursinus) (Male 1) with sarcoptic mange 100 days after infection with 4000 Sarcoptes scabiei.....241 Figure 8.30. Anaesthetised adult, male common wombat (Vombatus ursinus) (Male 2) with sarcoptic mange 100 days after infection with 8000 Sarcoptes scabiei.....241 Figure 8.31. Anaesthetised adult, female common wombat (Vombatus ursinus) (Female 1) with sarcoptic mange 100 days after infection with 6000 Sarcoptes scabiei...... 242 Figure 8.32. Anaesthetised adult, female common wombat (Vombatus ursinus) (Female 2) with sarcoptic mange 100 days after infection with 8000 Sarcoptes scabiei...... 242 Figure 8.33. Anaesthetised adult, female common wombat (Vombatus ursinus) (Female 3) with sarcoptic mange 100 days after infection with 8000 Sarcoptes scabiei...... 243 Figure 8.34. Weight loss (kg) of lactating female common wombats (Vombatus ursinus) with young at heel at Padilpa, Victoria, between August 1999 and November 2000...... 244 Figure 8.35. Population trajectories for density of Sarcoptes scabiei on free-living wombats when 30 larvae, 10 nymphs and 5 females occurred in a 25 cm2 area on 0 days after infection on the shoulder and λ=1.05 and λ=0.97 for a 2 day time interval, respectively...... 245 Figure 9.1. Emaciated, adult, male common wombat (Vombatus ursinus) from Steels Creek, Victoria, with hair loss and wounds on its rump and back in 1998...... 258

Minerva Access is the Institutional Repository of The University of Melbourne

Author/s: Skerratt, Lee Francis

Title: Sarcoptic mange in the common wombat, Vombatus ursinus (Shaw, 1800)

Date: 2001-07

Citation: Skerratt, L. F. (2001). Sarcoptic mange in the common wombat, Vombatus ursinus (Shaw, 1800). PhD thesis, Department of Veterinary Science, The University of Melbourne.

Publication Status: Unpublished

Persistent Link: http://hdl.handle.net/11343/39456

File Description: Title page & Preliminary pages

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