Background: There is little published research on prevalence of subclinical disease and cardiovascular abnormalities in apparently healthy mature adult dogs.
Hypothesis/Objectives: To describe prevalence of subclinical disease and cardiovascular examination abnormalities, and reasons for participant exclusion, in dogs screened for a clinical trial.
Animals: Reportedly healthy, client-owned, mature adult (>7-year-old) dogs screened for a large, prospective, randomized multicenter clinical trial.
Methods: Prior to in-clinic screening, electronic medical records of owner-nominated dogs were reviewed for evidence of systemic illness or treatment with an exclusionary drug. For each, signalment, body weight, and reason(s) for exclusion were recorded. For dogs subsequently screened in-person, indirect systolic arterial blood pressure (SBP), heart murmur presence, findings of echocardiography and electrocardiography, and any reason(s) for exclusion were recorded.
Results: 90 (29%) of 310 dogs were excluded prior to in-clinic screening, most commonly for exclusionary drugs or diagnoses (40.0% and 34.4% of excluded dogs, respectively). 50 (41%) of 121 dogs screened in-clinic were excluded, most commonly for a clinically significant cardiovascular or biospecimen abnormality (50% and 20% of excluded dogs, respectively). Degenerative mitral valve disease (DMVD) was diagnosed in 38 (33%) of 116 dogs undergoing echocardiography; of these, 18 (47%) had a heart murmur. Premature ventricular ectopy was documented in 20 (17%) of 117 dogs undergoing electrocardiography.
Conclusions and clinical importance: Cardiovascular abnormalities were common in this apparently healthy sample of mature adult dogs. Absence of a heart murmur in many dogs with DMVD suggests poor sensitivity of auscultation for this condition.
