Cat Stress Score and hair cortisol concentrations are not associated with subclinical hypertrophic cardiomyopathy in cats.

Hypertrophic cardiomyopathy (HCM) is a common heart disease in domestic cats, but most lack an identifiable cause. This prospective case-control study tested the hypothesis that chronic stress predisposes cats to HCM. Ten cats with echocardiographically confirmed subclinical HCM were compared with 10 healthy cats, HCM-negative cats matched for husbandry, age, sex, and neuter status. Stress was assessed via visual Cat-Stress-Score and hair cortisol concentrations, measured using an enzyme-linked immunosorbent assay from full-length hair samples collected from the lumbar region. Cat-Stress-Scores did not differ between groups across four time points (median 23.3 in the HCM group [range: 17.8-34.0] versus median 25.5 in the control group [range: 21.8-29.2], P = 0.241). Likewise, hair cortisol concentrations did not differ between groups (median 0.25ng/mL [range: 0.15-0.35] in the HCM group and median 0.19ng/mL [range: 0.09-0.29] in the control group, P = 0.267). In conclusion, cats with pre-existing subclinical HCM did not display greater stress than healthy controls on the measures of stress assessed.