Marcia R S Ilha Resident, Anatomic Pathology College of Veterinary Medicine University of Tennessee Case Number: 08-89 Presented at SEVPAC 2008 – Permission.

Marcia R S IlhaMarcia R S IlhaResident, Anatomic PathologyResident, Anatomic Pathology

College of Veterinary MedicineCollege of Veterinary MedicineUniversity of TennesseeUniversity of Tennessee

Case Number: 08-89Case Number: 08-89

Presented at SEVPAC 2008 – Permission Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website onlygranted for use on SEVPAC website only

SignalmentSignalment

16-month-old male wallaby 16-month-old male wallaby

Ollie Wallaby


HistoryHistory

lethargylethargywatery diarrheawatery diarrheadifficulty breathingdifficulty breathingmild uveitismild uveitisincreased ALT, ALP and CKincreased ALT, ALP and CKseizuresseizurescardiorespiratory arrestcardiorespiratory arrest

pet with access to yardpet with access to yardanother wallaby diedanother wallaby died


Gross findingsGross findings


Gross findingsGross findings


Gross Gross findingsfindings






HistopathologyHistopathology








Morphologic diagnosisMorphologic diagnosis

Cecum: Cecum: Diffuse, transmural, marked, Diffuse, transmural, marked, subacute, subacute, necrotizing typhlitis and necrotizing typhlitis and gut-associated gut-associated lymphoid tissue lymphoid tissue necrosis with necrosis with intralesional intralesional protozoan organisms protozoan organisms consistent consistent with with Toxoplasma gondiiToxoplasma gondii


SerologySerology

Positive for Toxoplasma gondii Positive for Toxoplasma gondii

[IgG > = 8192 UI/ml (>32 UI/ml positive)][IgG > = 8192 UI/ml (>32 UI/ml positive)]


HistopathologHistopathologyy

similar lesions stomach, small intestine, and colon

lymphadenitis of mesenteric lymph nodes

myocarditis, adrenalitis and thyroiditis

encephalitis

plasmacytic uveitis and choroiditis

interstitial pneumonia, hepatitis, and splenitis





Intralesional protozoan organisms consistent with T. gondii

stomach heartsmall intestine adrenal

gland colon thyroid gland cecum brainmesenteric lymph nodes eye mesentery

interstitial pneumonia, hepatitis, and splenitis (not observed)


ImmunohistochemistryImmunohistochemistry


ImmunohistochemistryImmunohistochemistry


DiscussionDiscussion

Wallabies and other Australian marsupials are among the most susceptible species to Toxoplasma gondii

Severe acute disease with widespread dissemination of the organism is frequently recognized

Contamination with T. gondii oocysts from domestic cats and wild felids is suspected as the main source of infection for herbivorous marsupials

In this case, feral cats were occasionally observed in the same area where the wallaby was kept

Most reported cases of fatal toxoplasmosis have been described in marsupials in captivity, especially in zoos


ReferencesReferences

Dubey JP et al. Toxoplasmosis in black-faced kangaroos Dubey JP et al. Toxoplasmosis in black-faced kangaroos (Macropus fuliginosus melanops). (Macropus fuliginosus melanops). Veterinary Veterinary ParasitologyParasitology; 30: 97-105. 1988.; 30: 97-105. 1988.

Johnson AM et al. Serodiagnosis of acute toxoplasmosis Johnson AM et al. Serodiagnosis of acute toxoplasmosis in macropods. in macropods. Veterinary ParasitologyVeterinary Parasitology; 34: 25-33. ; 34: 25-33. 1989.1989.

Miller MA et al. Outbreak of toxoplasmosis in wallabies Miller MA et al. Outbreak of toxoplasmosis in wallabies on an exotic animal farm. on an exotic animal farm. J Vet Diagn InvestJ Vet Diagn Invest; 4: 480-; 4: 480-483. 1992.483. 1992.

Basso W et al. Toxoplasmosis in captive Bennett’s Basso W et al. Toxoplasmosis in captive Bennett’s wallabies (wallabies (Macropus rufogriseusMacropus rufogriseus) in Argentina. ) in Argentina. Veterinary ParasitologyVeterinary Parasitology; 144: 157-161. 2007.; 144: 157-161. 2007.


AcknowledgementsAcknowledgements

Dr. Robert DonnellDr. Robert Donnell

Dr. Shelley NewmanDr. Shelley Newman

Histopathology Lab Staff, UTHistopathology Lab Staff, UT

UC Davis, IHCUC Davis, IHC


Questions?Questions?


Marcia R S Ilha Resident, Anatomic Pathology College of Veterinary Medicine University of Tennessee Case Number: 08-89 Presented at SEVPAC 2008 – Permission.

Documents

sevpac website

histopathology slide

immunohistochemistry

gross findings

gondii oocysts

toxoplasma gondii igg

herbivorous marsupials

uiml positive