Arterial pulses in dogs and cats

The strength and regularity of the peripheral arterial pressure waves and the pulse rate are assessed by palpation of the femoral or other peripheral arteries. Subjective evaluation of pulse strength is based on the difference between the systolic and diastolic arterial pressures (pulse pressure). When the difference is wide, the pulse feels strong on palpation; abnormally strong pulses are termed hyperkinetic. When the pressure difference is small, the pulse feels weak (hypokinetic). If the rise to maximum systolic arterial pressure is prolonged, as in animals with severe subaortic stenosis, the pulse also feels weak (pulsus parvus et tardus). Both femoral pulses should be palpated and compared; absence of pulse or a weaker pulse on one side may be caused by thromboembolism. Femoral pulses can be difficult to palpate in cats, even when normal. Often an elusive pulse can be found by gently working a fingertip toward the cat’s femur in the area of the femoral triangle, where the femoral artery enters the leg between the dorsomedial thigh muscles.
The femoral arterial pulse rate should be evaluated simultaneously with the direct heart rate, whick is obtained by chest wall palpation or auscultation. Fewer femoral pulses than heartbeats constitute a pulse deficit. Various cardiac arrhythmias indulce pulse deficits by causing the heart to beat before adequate ventricular filling has occured. Consequently, minimal or even no blood is ejected for those beats, and a palpable pulse is absent. Other arterial pulse variations occur occasionally. Alternately weak then strong pulsations can result from severe myocardial failure (pulsus alternans) or from a normal heartbeat alternating with a premature beat (bigeminy), which causes reduced ventricular filling and ejection. An exaggerated decrease in systolic arterial pressure during inspiration occurs with cardiac tamponade; a weak arterial pulse strength (pulsus paradoxus) may be detected during inspiration in such a case.