Prevalence of ocular lesions in cats newly diagnosed with histoplasmosis: 55 cases (2015-2022).

Abstract

OBJECTIVE: To describe the prevalence of ocular lesions in cats with newly diagnosed histoplasmosis. ANIMALS: 55 client-owned domestic cats. PROCEDURES: As part of this prospective case series, cats diagnosed with histoplasmosis between the years 2015 and 2020 underwent complete ophthalmic examinations by a board-certified veterinary ophthalmologist prior to the initiation of antifungal treatment. Histoplasmosis was diagnosed by consistent clinical findings and identification of Histoplasma yeast on pathology or by the use of a commercially available enzyme immunoassay to detect Histoplasma antigen in urine. RESULTS: Of the 55 cats, 45 (82%; 95% CI, 72% to 92%) had signs of active anterior, posterior, or panuveitis. The most common lesions were identified in the posterior portion of the globe and included chorioretinitis and partial retinal detachments (44/55 [80%; 95% CI, 69% to 90%] cats). CLINICAL RELEVANCE: Detailed ophthalmic examinations should be performed on all cats with diagnosed or suspected histoplasmosis, as ocular involvement and subsequent vision loss are common.