Prototheca zopfii is an alga that can cause disease in animals and humans.
Here, we reported a case of systemic protothecosis in a 2-year-old female
Boxer. The animal exhibited tetraparesis and vertical nystagmus. It died two
weeks after the onset of clinical signs and was necropsied. At gross
examination, whitish areas were identified in the heart. Oval or round
structures were observed by microscopic examination, some of which formed
morula-like structures compatible with algae in the heart, skeletal muscle,
and brain. Growth of Prototheca sp. was observed in the heart after culture at
37°C on Sabouraud agar medium with chloramphenicol. Immunohistochemical
analysis of the heart and brain using an anti-Prototheca zopfii polyclonal
antibody yielded positive results. Genotyping of the cultured agent from brain
and heart samples was performed by restriction fragment length polymorphism of
a specific 18S rDNA fragment. P. zopfii genotype 2 was reported to be the
cause of disseminated protothecosis in this dog with manifestation in the
brain, heart, and skeletal muscle