Protothecosis in 17 Australian dogs and a review of the canine literature.
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.
Stenner
V J
VJ
University of Queensland Veterinary Teaching Hospital, Queensland, Brisbane, Australia.
Mackay
B
B
King
T
T
Barrs
V R D
VR
Irwin
P
P
Abraham
L
L
Swift
N
N
Langer
N
N
Bernays
M
M
Hampson
E
E
Martin
P
P
Krockenberger
M B
MB
Bosward
K
K
Latter
M
M
Malik
R
R
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