Canine systemic protothecosis with ocular involvement: case report

Abstract

Protothecosis is an uncommon disease caused by a unicellular algae primarily found in organic matter, which affects humans, cattle, dogs, and cats, with a reserved to poor prognosis. The infection typically begins in the gastrointestinal tract, presenting as refractory diarrhea that persists for months before progressing to a systemic infection, involving other organs such as the eyes. The objective of this study was to report two cases of protothecosis in dogs that initially presented with gastrointestinal symptoms for several months before developing visual deficits and blindness. The diagnosis was made through histopathological examination of the eye and testicle, aiming to raise awareness among veterinary colleagues about the differential diagnosis of protothecosis in patients with ocular alterations associated with gastrointestinal diseases.