Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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IMPACTION OF THE OMASUM:
Etiology:
1. Occur when feed is tough and fibrous
Clinical findings:
1. Chronic recurrent bouts of indigestion occur
2. Decreased rumen motility
3. Infrequent and scanty feces
4. Refusal to eat grain and a negative ketone test
5. Pain may be elicited
6. Hard distended viscus palpated on deep pressure under the
right costal arch or in the seventh to ninth intercostal spaces
on the right side
7. It may also be palpable perrectum as a large, round, firm
mass with a checkered surface to distinguish it from the
smooth surface of the abomasum
Treatment:
Repeated dosing with mineral oil
LEFT-SIDE DISPLACEMENT OF THE ABOMASUM
ETIOLOGY:
1. Gaseous distension
2. Hypomotility of abomasum possibly due to feeding high
levels of concentrate to dairy
3. Cattle in late pregnancy
Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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Epidemiology:
1. High-producing dairy cows within 6 weeks of calving
2. Insufficient crude fiber and roughage in ration
3. Concurrent disease such as hypocalcemia and ketosis
PATHOGENESIS
1.
In the nonpregnant cow, the abomasum occupies the ventral
portion of the abdomen
2. As pregnancy progresses, the enlarging uterus occupies an
increasing amount of the abdominal cavity
3. A decline in plasma concentration of calcium around the time
of parturition may contribute to the abomasal atony.
4. The atonic gas-filled abomasum becomes displaced under the
rumen and upward along the left abdominal wall
5. The
6. displacement of the abomasum invariably results in rupture
of the attachment of the greater omentum to the abomasum
CLINICAL FINDINGS:
1. Complete anorexia
2. A marked drop in milk production
3. Varying degrees of ketosis
4. On inspection of the abdomen, the left lateral abdomen
appears 'slab-sided' because the rumen is smaller than normal
and displaced medially
5. Ruminal movements are commonly present but decreased in
frequency and intensity
6. Auscultation of an area below an imaginary line from the
center of the left paralumbar fossa to just behind the left
elbow reveals the presence of high pitched tinkling sounds
Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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7. Percussion, using a flick of the finger or a plexor, and
simultaneous auscultation over an area between the upper
third of the ninth and 12th ribs of the abdominal wall
commonly elicits the high-pitched tympanitic sounds (pings)
that are characteristic of LDA
8. Ultrasound examination can assist in the diagnosis of
abomasal displacements
DIFFERENTIAL DIAGNOSIS:
1. Simple indigestion is characterized by normal vital signs,
inappetence to anorexia, history of change of feed,
reduced milk production, a relatively full rumen with
reduced frequency and intensity of contractions, the
absence of pings and spontaneous recovery in 24 hours
2. Primary ketosis is characterized by inappetence, decline in
milk production, strong ketonuria, normal vital signs, full
rumen with reduced frequency and intensity of
contractions, dry but normal amount of feces and response
to therapy with dextrose and propylene glycol in 12-24
hours
3. Traumatic reticuloperitonitis in its acute form is
characterized by ruminal stasis, mild fever, a grunt on
deep palpation over the xiphoid sternum and a slight
neutrophilia with a regenerative left shift. However, in
subacute and chronic traumatic reticuloperitonitis a
painful
grunt may be absent, the temperature and hemogram may
be normal and on auscultation and percussion the atonic
rumen may be mistaken for an LDA. The tympanitic
sounds of an atonic rumen occur over a larger area than
with LDA and are not as high-pitched as those of LDA –
Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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they have been called 'pungs'. An exploratory laparotomy
may be necessary to distinguish between the two, although
laparoscopy, ultrasonography and abdominocentesis are
alternatives
4. Vagus indigestion is characterized by progressive
abdominal distension due to a grossly distended rumen
with or without an enlarged abomasum, and is more
common before parturition. Dehydration is also common
5. Fat cow syndrome at parturition is characterized by
excessive body condition, inappetence to anorexia,
ketonuria, reduced to absent reticulorumen motility, but
usually no pings over the rumen
TREATMENT:
1. Surgical correction is now commonly practiced and several
techniques have been devised with emphasis on avoidance of
recurrence of the displacement
2. Treatment of ketosis: Parenteral dextrose and oral propylene
glycol
Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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RIGHT-SIDE DISPLACEMENT OF THE ABOMASUM
AND ABOMASAL VOLVULUS:
ETIOLOGY:
1. is not well understood but it is probably similar to LDA
2. Abomasal atony is thought to be the precursor of dilatation
and displacement, and consequently abomasal volvulus
PATHOGENESIS
A. Dilatation and dis placement phase:
- abomasal atony occurs initially, resulting in the
accumulation of fluid and gas in the viscus leading to
gradual distension and displacement in a caudal
direction on the right side (dilatation phase)
B. Volvulus phase
- the distended abomasum may twist in a clockwise or
anticlockwise (viewed from the right side) direction in a
vertical plane around a horizontal axis passing
transversely across the body in the vicinity of the
omasoabomasal orifice. The volvulus will usually be of
the order of 180-270° and causes a syndrome of acute
obstruction with local circulatory impairment and
ischemic necrosis of the abomasum.
CLINICAL FINDINGS:
Dilatation phase:
1. Depression, Dehydration, no interest in feed, perhaps
increased thirst, muscular weakness.
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2. Affected cows will commonly sip water continuously
3. Percussion and simultaneous auscultation over the right
middle to upper third of the abdomen commonly elicits a
characteristic highpitched ping
in abomasal volvulus:
1. the clinical findings are usually much more severe than
during the dilatation phase
2. The abdomen is visibly distended
3. depression and weakness are marked, dehydration is obvious
4. the heart rate is 100-120/min and respirations are increased
Recumbency with a grossly distended abdomen and grunting
may occur and represents a poor prognosis
5. The feces are usually scant, soft and dark in color
CLINICAL PATHOLOGY
Serum biochemistry
1. There are varying degrees of hemoconcentration (increased
PCV and total serum proteins)
2. Metabolic alkalosis
3. Hypochloremia and hypokalemia
DIFFERENTIAL DIAGNOSIS:
Dilatation and displacement of abomasum
1. Impaction of the abomasum associated with vagus
indigestion
2. Subacute abomasal ulceration with moderate dilatation
3. Cecal torsion
4. Fetal hydrops
Medicine Lecture 4th Year 3-1-2017 Dr.Osamah Muwafk
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5. Chronic or subacute traumatic reticuloperitonitis
Abomasal volvulus
1. Intestinal obstruction
2. Acute diffuse peritonitis
TREATMENT:
1. Medical therapy for mild cases
2. Deflation of distended abomasum in calves
3. Surgical correction
4. Fluid and electrolyte therapy