Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 8
Figure 8.14 Percussion for anterior abdominal pain.
Acompass can be used to indicate the presence of a
prophylactic magnet in the reticulum. If a magnet is
found to be present, indicated by the movement of
the compass needle, traumatic reticulitis is less likely
to be the cause of the illness.
No physical examination of the left side of the
body is complete without checking for a left displaced
abomasum (Figs 8.15 and 8.16). Left displacement
of the abomasum is a very common condition
in high yielding dairy cows and is usually recognised
during the first few weeks after calving. Milk yield
and appetite are depressed. Ketosis is invariably
present and can be identified by a ‘pear drop’ smell
on the breath or by the presence of ketones in urine,
milk or saliva. Rothera tablets or the ketone patch on
a urine test stick can be used to confirm the presence
of ketones. The Rothera reagent turns purple in the
presence of ketones. Concurrent conditions such as
mastitis or endometritis are common.
The presence of a left displaced abomasum must always
be checked for during the examination of the abdomen of
adult cattle. In this condition the fluid and gas filled
displaced abomasum is between the left abdominal
wall and the rumen. Characteristic sounds are produced
by rising bubbles of gas and by the gas–fluid
interface within the displaced abomasum. The musical
tinkling sounds produced by escaping gas bubbles
can sometimes be heard by simple auscultation
using a stethoscope and are probably produced in response
to adjacent ruminal movements. Alternatively,
gentle ballottement of the abdomen using a
clenched fist or by gentle rocking may evoke them.
High pitched resonant pings can be produced by percussion
of the displaced abomasum. The pings may
be heard in association with the musical tinkling
sounds of escaping gas by simultaneous auscultation
using a stethoscope. The ping sounds like a basketball
being bounced upon a concrete floor or a steel
drum being hit.
The position and size of the displaced abomasum
are variable. It is suggested that clinical evaluation
should be focused along a line drawn from the left
elbow to the left tuber coxae, although it can be found
much higher or lower than this. In general, clinical
evaluation from the 9th to the 13th rib along this line
is often the most rewarding (Fig. 8.17). The resonance
produced by the gas cap of the rumen can sometimes
be misleading. This can usually be discounted by
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