CT scan signs of nasal cryptococcosis in Australian dogs and cats

Abstract

OBJECTIVE: To describe the CT findings of Australian dogs and cats with nasal cryptococcosis over a 12-year period. ANIMALS: 12 dogs and 9 cats diagnosed with nasal cryptococcosis from 2008 through 2020. METHODS: CT findings were compared among enrolled cases from Australian veterinary referral centers. Disease severity was compared between a subset of patients with cryptococcal speciation performed (n = 6 dogs; n = 3 cats) and geographic domicile. RESULTS: Dogs demonstrated diffuse disease affecting numerous nasal regions and sinuses. Cats displayed more focal nasal and nasopharyngeal disease. Dogs were more likely to have a nasal mass, whereas cats were more likely to have a nasopharyngeal mass. Cribriform plate lysis was common in dogs but not observed in cats. Sinonasal osteolysis was a common feature in both species. Mandibular lymph nodes were commonly enlarged in dogs, whereas in cats, the retropharyngeal lymph nodes were more likely enlarged. There was no obvious difference in disease severity or lesion distribution in relation to the causal species of Cryptococcus, although to determine if this finding is robust, an appropriately powered prospective study is warranted. CLINICAL RELEVANCE: There are numerous studies describing the clinical features, treatment, and outcomes of dogs and cats with cryptococcosis. To the best of our knowledge, there is only 1 previous study describing the CT features of nasal cryptococcosis, undertaken in one part of North America. Our study describes the CT features of nasal Cryptococcus sp in an Australian canine and feline cohort, adding new pertinent observations while reinforcing reported radiological observations.