Cryptococcus-targeted culture in dogs reveals nasal carriage of Naganishia albida and diverse opportunistic yeasts with potential clinical relevance.

OBJECTIVE: To investigate the nasal carriage of Cryptococcus-related and other opportunistic yeasts in dogs, molecularly characterize the recovered isolates, and evaluate the epidemiological characteristics of Naganishia albida carriage. METHODS: Nasal swab samples were collected from July through December 2023 from 100 dogs receiving boarding or hospitalization services at private veterinary clinics and animal hospitals in 4 provinces of Türkiye. Yeast isolates were identified using phenotypic methods, internal transcribed spacer 2 sequencing, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The 1-year clinical history of dogs carrying N albida was retrospectively reviewed. RESULTS: A total of 79 isolates representing 31 yeast species were identified from 59 dogs. Cryptococcus neoformans/gattii species complex organisms were not isolated from any dog. Naganishia albida and Papiliotrema laurentii were isolated from 12% and 1% of dogs, respectively. Naganishia albida carriage was detected in both clinically healthy and clinically affected dogs, with higher frequencies observed among dogs presenting with respiratory, dermatological, or systemic clinical findings. However, no significant associations were identified between N albida carriage and the evaluated epidemiological variables. CONCLUSIONS: Dogs may harbor diverse opportunistic yeasts, including Cryptococcus-related yeasts, within the nasal cavity. CLINICAL RELEVANCE: Opportunistic yeasts can colonize the nasal cavities of both clinically healthy and clinically affected dogs. These findings provide baseline epidemiological data for interpreting fungal culture results and contribute to a better understanding of opportunistic fungal carriage in companion animals.