BackgroundEpidemiologic knowledge regarding noncardiovascular and allâcause mortality in apparently healthy cats (AH) and cats with preclinical hypertrophic cardiomyopathy (pHCM) is limited, hindering development of evidenceâbased healthcare guidelines.ObjectivesTo characterize/compare incidence rates, risk, and survival associated with noncardiovascular and allâcause mortality in AH and pHCM cats.AnimalsA total of 1730 clientâowned cats (722 AH, 1008 pHCM) from 21 countries.MethodsRetrospective, multicenter, longitudinal, cohort study. Longâterm health data were extracted by medical record review and owner/referring veterinarian interviews.ResultsNoncardiovascular death occurred in 534 (30.9%) of 1730 cats observed up to 15.2âyears. Proportion of noncardiovascular death did not differ significantly between cats that at study enrollment were AH or had pHCM (P =â.48). Cancer, chronic kidney disease, and conditions characterized by chronic weightâlossâvomitingâdiarrheaâanorexia were the most frequently recorded noncardiovascular causes of death. Incidence rates/risk of noncardiac death increased with age in AH and pHCM. Allâcause death proportions were greater in pHCM than AH (65% versus 40%, respectively; P <â.001) because of higher cardiovascular mortality in pHCM cats. Comparing AH with pHCM, median survival (study entry to noncardiovascular death) did not differ (AH, 9.8âyears; pHCM, 8.6âyears; P =â.10), but allâcause survival was significantly shorter in pHCM (Pâ= .0001).Conclusions and Clinical ImportanceAllâcause mortality was significantly greater in pHCM cats due to disease burden contributed by increased cardiovascular death superimposed upon noncardiovascular death.