Protothecosis with ocular involvement in a dog.

An 8 1/2-year-old Collie dog was referred for evaluation of chronic diarrhea as well as sudden blindness and leukokoria of the right eye. An organism morphologically similar to Prototheca sp was recovered from the subretinal fluid and was found at necropsy in the eyes, gastrointestinal tract, lungs, lymph nodes, kidneys, heart, abdominal fat, and omentum.