Disseminated protothecosis with central nervous system involvement in a dog.

A 4-year-old mixed-breed spayed bitch was euthanatized after 2 1/2 months of progressive neurologic disease. Prototheca organisms were identified by histopathology, culture, and electron microscopy. Specific fluorescent antibody procedures revealed two species--Prototheca wickerhamii and Prototheca zopfii. Organisms and pyogranulomatous lesions were found in the brain, spinal cord, right eye, kidneys, and heart.