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

Cardiovascular (CVS) disease is a major cause of morbidity and mortality in felines with hypertrophic cardiomyopathy (HCM), showing the highest incidence rate of CVS-related deaths. Despite advanced diagnostic tools like echocardiography, electrocardiogram and cardiac biomarkers, many cases remain underdiagnosed due to sudden death and asymptomatic. This study retrospectively evaluated the prevalence, gross and histopathological characteristics of cardiovascular lesions in feline necropsy cases encountered at 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, representing 22.13% of the 235 total necropsy submissions during the study period. The findings revealed an increasing trend in feline necropsy prevalence, with the highest recorded rate of 36% in 2025. Histopathological cardiovascular lesions were identified in 69.23% of 52 feline necropsy cases examined between 2020 and June 2025, showing an overall increasing trend with a transient decline from 75% to 50% between 2021 and 2023 and a peak prevalence of 88.89% as of June 2025. Infectious diseases and trauma, including wound-related, motor vehicle, and high-rise trauma, were the most common antemortem diagnoses. Kittens (birth to one year old), male cats, and domestic shorthair (DSH) breeds represented the highest proportions of necropsy submissions at 46.15%, 65.28%, and 76.92%, respectively. The most frequently observed feline cardiovascular gross lesions were left ventricular hypertrophy (53.57%), congestion (46.43%), pericardial effusion (39.29%), and valvular endocardiosis (35.37%). Histopathologically, the predominant lesions were myocardial fibrosis (59.46%), myocarditis (56.76%), ventricular hypertrophy (51.36%), and ventricular dilatation (40.54%). Fisher’s exact test demonstrated no significant association between antemortem diagnosis (infectious, non-infectious, trauma-related, and congenital anomalies) and the cardiovascular histopathological lesions (myocardial fibrosis, myocarditis, ventricular hypertrophy and ventricular dilatation) (p > 0.05), although infectious and trauma-related causes appeared to contribute to the lesions’ development. This study provides insights into the prevalence and characteristics of feline cardiovascular lesions in Malaysia, enhancing the understanding of their potential causes and aiding clinicians in improving diagnosis, treatment and prognosis of feline cardiovascular diseases.