Cardiomyopathy prevalence in 780 apparently healthy cats in rehoming centres (the CatScan study)

Abstract

ObjectivesHypertrophic cardiomyopathy (HCM) appears to be common in cats and, based on pilot data, a prevalence of 15% has been hypothesized. The objectives were to screen a large population of apparently healthy adult cats for cardiac disease, and identify factors associated with a diagnosis of HCM. AnimalsA total of 1007 apparently healthy cats ≥6 months of age. MethodsIn this prospective, cross-sectional study, the inclusion criteria were: apparently healthy cats, aged ≥6 months, available for rehoming over a 17-month period from two rehoming centres. Hypertensive or hyperthyroid cats were excluded. Body weight, body condition score, auscultation, systolic blood pressure and two-dimensional (2-D) echocardiography were evaluated. Cats with left ventricular end-diastolic wall thickness ≥6 mm on 2-D echocardiography were considered to have HCM. ResultsComplete data were obtained in 780 cats. Heart murmur prevalence was 40.8% (95% confidence interval (CI) 37.3–44.3%), 70.4% of which were considered functional. The prevalence of HCM was 14.7% (95% CI 12.3–17.4%), congenital disease 0.5% (95% CI 0.1–1.3%), and other cardiomyopathies 0.1% (95% CI 0.0–0.7%). The HCM prevalence increased with age. The positive predictive value of a heart murmur for indicating HCM was 17.9–42.6% (higher in old cats), and the negative predictive value was 90.2–100% (higher in young cats). The factors associated with a diagnosis of HCM in binary logistic regression models were male sex, increased age, increased body condition score and a heart murmur (particularly grade III/VI or louder). ConclusionsHypertrophic cardiomyopathy is common in apparently healthy cats, in contrast with other cardiomyopathies. Heart murmurs are also common, and are often functional.