Medycyna Wet. 64 (2), 156-160, 2008
Gaálová M., Fialkovičová M., Kozák M., Máteová S.
Cardiovascular system abnormalities in a dog with primary hypothyroidism
The thyroid hormones have direct and indirect effects on the heart. Therefore, it is possible that depression of left ventricular functioning is associated with hypothyroidism. This article describes the case report of primary hypothyroidism in a dog with dominant clinical findings (clinical examination, ECG, echocardiography) associated with the cardiovascular system. Low heart rates, reduced R-amplitudes and bradycardic arrhythmias (first-degree AV block) were noted on an electrocardiogram before treatment. On the echocardiogram, the dog showed reduced contractility and reduced left ventricular wall thickness. The patient was re-examined after levothyroxine supplementation. Effects of treatment included increased heart rates, mildly increased R amplitudes, and the disappearance of bradyarrhythmias in ECG examination. The echocardiographic examination showed increased contractility and increased left ventricular wall thickness.
Keywords: dog, hypothyroidism, cardiovascular system