Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 8
toneum) which may be pathological but may have
been caused by the abdominocentesis procedure
puncturing a blood vessel during sampling. Repeating
the procedure at a different site may allow the
two possibilities to be differentiated.
A turbid sample indicates an increased protein and
cellular content. Large quantities of yellowishcoloured
turbid fluid (sometimes with fibrin tags)
suggest acute diffuse peritonitis. A sample that forms a
generous stable froth after vigorous shaking indicates
the presence of intra-abdominal inflammatory processes
caused by the increased protein content of the
peritoneal fluid. Clotting of the sample indicates an
increase in the viscosity of the peritoneal fluid due to
inflammatory processes.
More detailed laboratory analysis may include
measurements of specific gravity and protein content.
Ahigh specific gravity and high protein content suggest
vascular damage and leakage of plasma proteins
in peritonitis or ischaemic necrosis of the bowel. Microscopy
may indicate the presence of particulate
food material from a ruptured bowel. Cytology may
indicate an increased white blood cell (WBC) count
of the peritoneal fluid with increased polymorphonuclear
cells (PMN) which indicates inflammation
(sterile or infectious), the presence of degenerative
PMNs which suggests infection, and increased
monocytes which suggests the presence of a
chronic inflammatory process.
Table 8.2 provides a classification of normal, transudate,
modified transudate and exudate peritoneal
fluids. Atransudate may be present in Johne’s disease
as a result of hypoproteinaemia. Amodified transudate
may be observed in lymphosarcoma of the gastrointestinal
tract or congestive heart failure. An exudate
may be septic or non-septic. Conditions causing a
septic exudate include a ruptured infected uterine
metritis and a traumatic reticuloperitonitis. A condition
causing a non-septic exudate is a ruptured
bladder.
Radiography
Radiography of the anterior abdomen may be useful
in the diagnosis of traumatic reticulitis caused by a
penetrating wire. However, powerful machines are
required that are usually only available in referral
centres. It can be useful in young valuable calves.
Metal detectors
Metal detectors have been used to rule out the presence
of metal in the structures of the anterior abdomen.
However, many normal cattle give positive
results due to the presence of harmless metal fragments
present in the reticulum. Examples are the
ends of anthelmintic boluses and nuts and bolts.
Ultrasonography
Ultrasonography is non-invasive and is useful for
investigating conditions of the umbilicus, gastrointestinal
tract and liver. The equipment required includes
a 5 or 3.5 MHz linear transducer, clippers and
contact gel. The hair is removed using clippers. Liberal
quantities of contact gel are applied to the
clipped area of skin to ensure contact. The presence
of fluid and adhesions in the abdomen can be
detected. The abomasum and reticulum can be
visualised using ultrasonography.
Infections of the umbilicus, the umbilical arteries,
the umbilical veins and urachus are relatively common
in calves. Apatent urachus may also be present.
Ultrasonography is very useful in identifying gross
abnormalities of these structures. The hair of the ventral
abdomen must be clipped and liberal amounts of
contact gel applied to ensure a contact. It is best to
begin the ultrasonography over the umblicus. Any
abnormal structures can then be traced cranially (the
umbilical vein(s)) or caudally (the umbilical arteries
and urachus). It is important to scan the ventral
abdomen from the umbilicus to the liver and the
umbilicus to the bladder systematically, otherwise
abnormalities may be missed. Enlarged and pus
filled structures can be readily identified. The contents
of umbilical hernias can also be evaluated.
The liver can be identified through the intercostal
spaces 6 to 12 on the right side. Liver enlargment and
liver abscessation may be detected. The caudal vena
cava may be examined between ribs 11 and 12, and
the gall bladder between the 9th, 10th or 11th intercostal
spaces.
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