Prevalence of and Risk Factors for Degenerative Mitral Valve Disease in Dogs Attending Primary‐care Veterinary Practices in England

BACKGROUND: To date, epidemiological studies on degenerative mitral valve disease (DMVD) in dogs have largely reported referral caseloads or been limited to predisposed breeds. Analysis of primary‐care data to identify factors associated with DMVD would help clinicians identify high‐risk individuals and improve understanding. OBJECTIVES: To estimate the prevalence of and identify risk factors for DMVD in dogs attending primary‐care veterinary practices in England. ANIMALS: Cases were identified within the electronic patient records of 111,967 dogs attending 93 practices. Four hundred and 5 dogs were diagnosed with DMVD (diagnosed cases) and a further 3,557 dogs had a heart murmur (HM) consistent with DMVD (possible cases). METHODS: Retrospective cross‐sectional study design. Prevalence was adjusted for the sampling approach. Mixed effects logistic regression models identified factors associated with DMVD. RESULTS: Prevalence estimates of diagnosed DMVD and HMs consistent with DMVD (both diagnosed and possible cases) were 0.36% (95% confidence interval [CI]: 0.29–0.45) and 3.54% (95% CI: 3.26–3.84) respectively. In the multivariable analysis, males had higher odds of diagnosed DMVD than did females (odds ratio [OR] 1.40, 95% CI: 1.12–1.74). Insured dogs had increased odds of DMVD compared with noninsured dogs (OR 3.56, 95% CI: 2.79–4.55) and dogs ≥20 kg had approximately half the odds of DMVD diagnosis compared with dogs <20 kg (OR 0.51, 95% CI: 0.36–0.74). Strong associations between a DMVD diagnosis and individual breeds and age were identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Degenerative mitral valve disease was a common disorder in practice‐attending dogs. Knowledge of identified risk factors for DMVD could improve clinical diagnosis and direct future research.