Echocardiographic measurement of cardiac valvular thickness in healthy cows, cows with bacterial endocarditis, and cows with cardiorespiratory diseases.

Objective: To determine valvular thickness in healthy cows, cows with bacterial endocarditis, and cows with various cardiorespiratory diseases.

Animals: 40 healthy Holstein adult cows (CONTROL), 6 adult cows with confirmed bacterial endocarditis (BE), and 10 cows with other cardiorespiratory disorders (NONBE).

Methods: Prospective study using right transthoracic echocardiographic examination in CONTROL, BE and NONBE cows. The valvular thicknesses of all cows were assessed in four different locations for all cardiac valves, and the maximal value was used for further analysis.

Results: The mean [±standard deviation (SD)] maximal thicknesses of the tricuspid, mitral, aortic, and pulmonary valves in the CONTROL group were 0.69 ± 0.10 cm, 0.85 ± 0.21 cm, 0.72 ± 0.17 cm, and 0.58 ± 0.12 cm, respectively. The maximal valvular thicknesses were less than 0.97 cm for the tricuspid, less than 0.91 cm for pulmonary, less than 1.05 cm for the aortic, and less than 1.28 cm for the mitral. In BE cows, the maximal valvular thickness of affected valves (median: 4.22 cm; range: 2.52-6.97 cm) and non affected valves (median: 0.75 cm; range: 0.45-1.52 cm) were significantly different (P = 0.0004). The maximal valvular thicknesses of the NONBE valves as well as the unaffected valves in the BE group were not significantly different compared to the CONTROL group valves.

Conclusions: Using the mean ± 2SD formula for each valve in healthy cows, a thickness of tricuspid, mitral, aortic or pulmonary valves greater than 0.85 cm, 1.27 cm, 1.06 cm or 0.82 cm respectively should raise the suspicion of valvular bacterial endocarditis.