Patterns of morbidity, multimorbidity, and mortality in aging cats: findings from seven years of the Cat Prospective Ageing and Welfare Study.

Introduction: Aging is associated with an increased risk of morbidity, multimorbidity and mortality in cats. However, longitudinal cohort studies are somewhat limited in this species. Information about the prevalence and incidence of age-related disease, combinations of morbidities, and factors associated with mortality could provide insights into the impact of aging on the welfare of domestic cats. Methods: The prevalence and incidence of common age-related diseases, patterns of multimorbidity and causes and risk factors for mortality were investigated in a prospective longitudinal cohort study of 209 aging cats. Cats were enrolled at middle age and attended a veterinary examination every 6 months, until death or censoring, for up to 7 years. Results: A total of 1,241 examinations were performed (median follow-up 4.4 years; range 0.0-6.9). Dental disease (84%), abnormalities on orthopedic examination (82%) and heart murmurs (59%) were most prevalent within the cohort over the study period. Most cats (96%) developed at least one abnormality on veterinary examination, and multimorbidity was common, with 175 cats (84%) developing two or more morbidities during the study. Death occurred in 59/209 cats (28%) and median life expectancy was 15.2 years. Pedigree cats had approximately double the hazard of mortality (HR 2.62, 95%-CI 1.39, 4.93; Discussion: These findings demonstrate that age-related morbidity and multimorbidity are highly prevalent in cats and both should be considered by veterinary professionals examining these older animals. Furthermore, we identified that midlife body condition, muscle condition and pedigree status affected mortality risk, highlighting the importance of assessing these factors in practice and suggesting that targeted strategies to promote healthy aging should start from middle age.