Cats with idiopathic chronic rhinosinusitis that develop clinical signs before two years of age have more severe nasal conchal lysis, sinus malformation, and more severe inflammation on histological examination.

Abstract

OBJECTIVE: To evaluate the severity of sinonasal lesions on CT in cats with feline idiopathic chronic rhinosinusitis (FICR) comparing cats who developed the condition at a young age to those who developed it as an adult. And, to assess if CT findings correlate with histopathology. ANIMALS: 58 cats with FICR confirmed on histopathology. METHODS: Medical records were retrospectively reviewed. Cats were divided into 2 groups based on their age category: juvenile (group 1, n = 30) and adult (group 2, 28), with juvenile cats being 2 years old or younger and adults being older than 2 years at the onset of clinical signs. Computed tomographic findings were recorded and graded (mild, moderate, and severe) by a board-certified radiologist, comparing each group. The CT findings were then compared to the histopathology results. RESULTS: The overall CT grade was not significantly different between the 2 groups (P = .21). Nasal conchal lysis was more severe in group 1 than in group 2 (P = .002), and group 1 also had a higher incidence of sinusal malformation (OR 2.42). Inflammatory infiltrates were more severe on histopathology in group 1 than in group 2 (OR 4.95), and the overall CT grade was slightly positively associated with the histological severity (κ = 0.2). CLINICAL RELEVANCE: Feline idiopathic chronic rhinosinusitis was associated with more severe nasal conchal lysis, sinus malformation, and more severe inflammation on histopathological examination in cats that develop clinical signs before 2 years of age. This finding could have an impact in term of clinical signs severity.