Retrospective evaluation of pulmonary lesions in cats: prevalence, gross, and histopathological findings encountered from necropsy cases at pathology laboratory, Veterinary Diagnostic Centre (UVDC), Universiti Malaysia Kelantan (UMK) from 2020 to 2025

Pneumonia is the infection of lungs which is less commonly reported in cats compared to feline upper respiratory tract disease (FURD), that possibly is underdiagnosed. Despite the advancement in diagnostic tools like radiography, pneumonia remains underdiagnosed sometimes due to the inapparent radiographic findings, and the other diagnostic tests are either showing less pulmonary specific result like hematology, or it is invasive to perform like biopsy. Thus, this retrospective study was conducted to determine the prevalence and types of feline necropsy cases and to characterize the common pulmonary lesions in cats submitted to the Pathology Laboratory, University Veterinary Diagnostic Centre (UVDC), Universiti Malaysia Kelantan (UMK) from 2020 to June 2025. A total of 52 feline necropsy cases were reviewed and categorized into Infectious, Non-infectious, Trauma (wound), Trauma (motor-vehicle/high-rise), and Others based on antemortem diagnosis. The Infectious category was the most prevalent (51.9%), followed by Trauma (motor-vehicle/high-rise) (15.4%) and Non-infectious (11.5%). Domestic Shorthair (DSH) cats represented most cases (76.9%), and male cats (65.4%) were more frequently affected. Kittens constituted the largest age group (46.2%), consistent with their increased susceptibility to infectious diseases. Grossly, pulmonary congestion (84.6%), pulmonary edema (76.9%), and pulmonary atelectasis (73.1%) were the most frequent lesions. Histopathologically, pulmonary atelectasis and emphysema were most common, followed by pulmonary edema (80.0%) and interstitial pneumonia (57.5%). Interstitial pneumonia was more prevalent than suppurative bronchopneumonia, and two cases of fungal pneumonia were also recorded. This study also highlighted that interstitial pneumonia may be underdiagnosed in felines and the importance of fungal pneumonia to be included in the differential diagnosis for every patient presented with respiratory distress.