Page 989 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

964 CHAPTER 8

VetBooks.ir ing the relative importance and potential effect of 8.1
The age of the animal is of value in consider-

an abnormal finding. Congenital heart disease is
most frequently detected in the neonatal animal.
Functional murmurs are common in fit, young per-
formance animals. Valvular disease has an increased TV
prevalence in older animals. The detection of a mur-
mur consistent with aortic valvular regurgitation
may be of greater significance in a young animal
than it would be in an aged horse, where such mur- F
murs are relatively common.

General examination
The general appearance of an animal may indicate Fig. 8.1 Areas on the head for palpation of the
the extent and duration of disease. Poor body con- peripheral pulse. The transverse facial artery (TV)
dition may indicate advanced or chronic disease. is palpable caudoventral to the eye (this vessel is also
Mucous membrane evaluation can be used to assess useful for arterial blood sampling in adults). The facial
peripheral circulation and hydration status. Mucous artery (F) is palpable over the mandible rostral to the
membranes in the normal animal should be pale masseter muscle.
pink, with a capillary refill time (CRT) of less than
2 seconds. Alterations in mucous membrane colour reflux of blood into the jugular vein from the right
or CRT are not specific to cardiac disease. heart occurs, is uncommon except in advanced right-
The jugular veins in a horse can be used to assess sided heart disease/failure.
cardiovascular status. First, the patency of the jug- Peripheral pulses should be assessed. The most
ular veins should be assessed. Partial or complete common sites are at the facial or transverse facial
obstruction from thrombosis secondary to repetitive arteries (Fig. 8.1). The rate and the rhythm of pulsa-
or traumatic i/v injection is common in the horse, tion should be assessed as well as the pulse strength.
and both jugular veins must be assessed for extent The pulse rate should be compared with the
of fill and the symmetry between them. A distended auscultated heart rate to evaluate for pulse deficits.
jugular vein indicates obstruction to venous return Saphenous arterial pulses should be compared when
because of either external compression of the jugular aortoiliac thrombosis is a concern. Palpation p/r is
vein or right-sided heart failure. Slight pulsations at also indicated to assess the divisions of the aorta in
the thoracic inlet are a normal finding. The extent of these cases.
the pulsation should be assessed; in a standing horse, The presence and extent of oedema should be
with a normal head position, the pulsations generally assessed. Limb oedema is relatively common in the
extend less than one-third of the way up the jugular horse and is not usually associated with cardiac dis-
vein. The rate and rhythm of the jugular pulsations ease. While ventral oedema occurs in heart failure,
can also be observed, and a variable extent and rate differential diagnoses such as hypoproteinaemia and
of jugular fill are findings suggestive of arrhythmia. pleural effusion should be considered.
The jugular vein should be obstructed at the base of Careful auscultation of the lung fields should be
the neck and the rate of fill all the way to the jawline performed as part of the cardiovascular examination
assessed. Slow jugular fill may indicate poor venous because respiratory signs occur in left-sided heart
return because of either poor hydration or cardiac failure and respiratory disease is a differential diag-
failure. The vein should be then obstructed at the nosis for suboptimal performance.
top and allowed to empty. Emptying should occur Thoracic percussion should be performed both
within a single cardiac cycle. Poor emptying or per- to assess the location and distribution of the apex
sistence of pulsations within the jugular vein, once beat and to detect the presence of a cardiac thrill.
emptied, is abnormal. A true jugular pulse, where The cardiac impulse is normally palpable on the left