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.

Prototheca miyajii sp. nov., isolated from a patient with systemic protothecosis

“…Currently, six species are included in the genus Prototheca: Prototheca wickerhamii, Prototheca zopfii, Prototheca blaschkeae, Prototheca cutis, Prototheca ulmea and Prototheca stagnora (Roesler et al, 2006;Satoh et al, 2010;Roesler, 2011). The first four species have been shown to cause infections in animals, such as cattle and dogs (Frank et al, 1969;Hollingsworth, 2000;Jánosi et al, 2001;Stenner et al, 2007), and humans (Matsuda & Matsumoto, 1992;Lass-Flörl & Mayr, 2007;Todd et al, 2012). Recently, an increasing number of human cases of protothecosis have been reported, including opportunistic infection in immune-compromised individuals (Todd et al, 2012).…”

Prototecose em animais de companhia e aspectos da doença no homem

“…Diarréia com sangue intermitente é o sinal clínico mais freqüentemente relatado (HOLLINGSWORTH, 2000). Nos casos disseminados, P. zopfii é a espécie mais comumente isolada (STENNER et al, 2007).…”

“…Estas drogas também são utilizadas no tratamento de casos sistêmicos. Entretanto, o sucesso da terapia da prototecose em animais de companhia é controverso entre os autores (TYLER et al, 1980;FONT & HOOK, 1984;DILLBERGER et al, 1988;GINEI et al, 1997;HOLLINGSWORTH, 2000;RALLIS et al, 2002;HOSAKA & HOSAKA, 2004;GREENE, 2006;STENNER et al, 2007). De acordo com LASS-FLÖRL & MAYR (2007), a ação variável de drogas antifúngicas frente às algas do gênero Prototheca pode ser explicada pela presença de ergosterol, substância presente primariamente na parede celular de fungos na parede celular do microrganismo.…”

Prototheca zopfii genotype 2 disseminated infection in a dog with neurological signs

“…Protothecosis has been reported in humans (CARNEIRO et al, 2007) and animals, including bovines (ROESLER et al, 2003), caprines (MACEDO et al, 2008), canines (COOCK et al, 1984;STENNER et al, 2007;SALVADORI et al, 2008;RIBEIRO et al, 2009) and felines (DILLBERGER et al, 1988;HUTH et al, 2015), and is caused by multiple species: P. ulmea, P. stagnora, P. blaschkeae, P. zopfii, and P. wickerhamii. The last two are considered pathogenic to dogs (TSUJI et al, 2006;SIQUEIRA et al, 2008).…”

“…Infection is acquired through ingestion or contact with non-intact skin or mucous membranes (STENNER et al, 2007;PRESSLER, 2012).…”