to CAL cardiology page.
apex of the heart lies caudal to the elbow at the sixth
intercostal space. The base of the heart lies cranial to
the elbow. The aortic, pulmonic and mitral valves are
ausculted on the left side of the heart. Insert your
stethoscope deep under the axilla to find the pulmonic valve
area between the shoulder and the elbow at the left third
intercostal space. The aortic valve area is located at the
left fourth intercostal space at the level of the shoulder.
The mitral valve is located between the shoulder and elbow at
the fifth intercostal space. Auscultation
should take place in a reasonably quiet environment.
The most successful way of examining the heart is to place
the bell of the stethoscope sufficiently forward between the
upper foreleg and the chest wall. The heart is located in
the ventral part of the thorax between the third and sixth ribs.
Careful interpretation of rate, rhythm, and heart sounds is
necessary. It is also advised to observe the jugular vein
and mammary vein for any signs of distention or pulsation while
you are ausculting the heart. Most dairy cows with cardiac
disease have tachycardia at rest, but many diseases result in
high heart rates (such as infectious diseases).
Bradycardia (40-60 bpm) is often associated with vagal
indigestion. Muffled heart sounds occur with
pericardial and pleural effusion. Increased intensity of
the heart sounds is associated with increased cardiac
contractility. Cardiac diseases such as bacterial
endocarditis and some cases of lymphosarcoma can be accompanied
by fevers. The most common cause of murmurs is bacterial
endocarditis. The most common valve is the tricuspid on
the right side followed by the mitral valve on the left.
Cardiac diseases may occur secondarily to GI diseases such as
"hardware", traumatic reticulopericarditis.
Muffled heart sounds with or without a washing machine-like
murmur, distended jugular veins, jugular pulse and brisket edema
are compatable findings with hardware disease. Atrial
fibrillation causes a irregularly, irregular heart beat, and is
generally associated with a GI problem such as an LDA.
Brisket and ventral edema.
in the neck and brisket area are often associated with cardiac
disease, or low plasma protein as is seen with Johne's disease,
enteritis, or parasitism.
jugular and abdominal veins should be palpated to assess the
venous system. Distention of these veins are indicative of
increased venous pressure. Assessment of the jugular
pulses is best done with the head elevated and it is normal to
see pulses at the level of the heart. With the head being
elevated, make sure nothing is occluding the jugular veins to
give a false positive. The vein will fail to empty with
the occlusion of the vein with your hand and then the release of
the occlusion when cardiac disease is present.
* Normal resting heart
rate is 60 - 80 bpm. (Calves = 110 - 120 bpm.)
Click on your next PE point to continue with
your physical exam.