title: Protothecosis in 17 Australian dogs and a review of the canine literature.
abstract: Systemic protothecosis was diagnosed in 17 Australian dogs between 1988 and 2005. There was a preponderance of young-adult (median 4 years), medium- to large-breed dogs. Females (12/17 cases) and Boxer dogs (7 cases, including 6 purebreds and one Boxer cross) were over-represented. Sixteen of 17 dogs died, with a median survival of four months. A disproportionate number of cases were from coastal Queensland. In most patients, first signs were referable to colitis (11/17 cases), which varied in severity, and was often present for many months before other symptoms developed. Subsequent to dissemination, signs were mostly ocular (12 cases) and/or neurologic (8 cases). Two dogs had signs due to bony lesions. Once dissemination was evident, death or euthanasia transpired quickly. Prototheca organisms had a tropism for the eye, central nervous system (CNS), bone, kidneys and myocardium, tissues with a good blood supply. Microscopic examination and culture of urine (5 cases), cerebrospinal fluid (CSF;1 case), rectal scrapings (4 cases), aspirates or biopsies of eyes (5 cases) and histology of colonic biopsies (6 cases) as well as skin and lymph nodes (2 cases) helped secure a diagnosis. Of the cases where culture was successful, P wickerhamii was isolated from two patients, while P zopfii was isolated from five. P zopfii infections had a more aggressive course. Treatment was not attempted in most cases. Combination therapy with amphotericin B and itraconazole proved effective in two cases, although in one of these treatment should have been for a longer duration. One surviving dog is currently still receiving itraconazole. Protothecosis should be considered in all dogs with refractory colitis, especially in female Boxers.
authors.affiliation: University of Queensland Veterinary Teaching Hospital, Queensland, Brisbane, Australia.
authors.forename: V J
authors.initials: VJ
authors.lastname: Stenner
authors.forename: B
authors.initials: B
authors.lastname: Mackay
authors.forename: T
authors.initials: T
authors.lastname: King
authors.forename: V R D
authors.initials: VR
authors.lastname: Barrs
authors.forename: P
authors.initials: P
authors.lastname: Irwin
authors.forename: L
authors.initials: L
authors.lastname: Abraham
authors.forename: N
authors.initials: N
authors.lastname: Swift
authors.forename: N
authors.initials: N
authors.lastname: Langer
authors.forename: M
authors.initials: M
authors.lastname: Bernays
authors.forename: E
authors.initials: E
authors.lastname: Hampson
authors.forename: P
authors.initials: P
authors.lastname: Martin
authors.forename: M B
authors.initials: MB
authors.lastname: Krockenberger
authors.forename: K
authors.initials: K
authors.lastname: Bosward
authors.forename: M
authors.initials: M
authors.lastname: Latter
authors.forename: R
authors.initials: R
authors.lastname: Malik
mesh_terms: D000367:Age Factors; D000818:Animals; D001315:Australia; D001706:Biopsy; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology; D002490:Central Nervous System / Q000473:pathology; D015331:Cohort Studies; D003092:Colitis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D003106:Colon / Q000382:microbiology / Q000473:pathology; D004283:Dog Diseases / Q000382:microbiology* / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D004285:Dogs; D005123:Eye / Q000473:pathology; D005260:Female; D006651:Histocytochemistry; D007239:Infections / Q000150:complications / Q000382:microbiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D007668:Kidney / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000473:pathology; D011525:Prototheca / Q000302:isolation & purification*; D011859:Radiography; D012007:Rectum / Q000382:microbiology; D012189:Retrospective Studies; D012737:Sex Factors