A case report of Penicillium chorioretinitis in a Border Collie dog.

Systemic fungal pathogens typically gain entry through a single portal and disseminate to affect multiple body systems. Infections caused by fungal Penicillium species are rare in dogs, and these cases have a poor prognosis. An unknown Penicillium species was isolated from the right eye of a middle-aged Border Collie without evidence of systemic disease. Due to financial limitations, an extensive diagnostic evaluation could not be performed. Histopathology alone failed to identify the specific causative agent; however, fungal culture on aqueous humor provided the definitive diagnosis. This case highlights the advantage of collecting ocular fluids after enucleation to diagnose atypical fungal infections.