Displaced Abomasum

Displaced abomasum (DA) is one of the most common surgical disorders of dairy cattle. It occurs when the abomasum fills with gas and rises from its normal ventral position to lie between the rumen and the left (LDA) or right (RDA) body wall.

Left displaced abomasum (LDA):

• Most common (~85% of DAs)
• Abomasum rises to the left side, trapped between the rumen and left abdominal wall
• Occurs most commonly 2–6 weeks postpartum (peak incidence ~3 weeks)

Right displaced abomasum (RDA):

• Less common (~15%)
• Abomasum displaces to the right side
• More likely to progress to volvulus (torsion) than LDA

Right abomasal volvulus:

• RDA + 180–360° rotation around mesenteric axis
• Severe distension, vascular compromise, endotoxemia, shock
• Surgical emergency; guarded prognosis

Risk factors:

• Hypocalcemia (decreased abomasal motility)
• Ketosis (negative energy balance)
• High-concentrate diet (fermentation gas, decreased fiber)
• Retained placenta, metritis, mastitis (decreased feed intake)
• Twins, dystocia, cesarean (periparturient stress)
• Obesity (fatty liver)

Clinical signs:

• Decreased milk production (first sign often noticed by farmer)
• Anorexia (often partial — may eat grain but not hay)
• Scant, dry feces
• Mild dehydration
• Ketosis (acetone breath, positive urine ketones)

Physical exam:

• Simultaneous auscultation and percussion: High-pitched metallic ping over the left (LDA) or right (RDA) lower flank/paralumbar fossa. The ping is characteristic — resonant, high-pitched, and localized.
• Ballottement: Splashing or fluid sounds may be audible
• Rectal exam: For LDA, the abomasum may be palpated as a gas-distended viscus between the rumen and left body wall. For RDA, palpation is more difficult but may reveal distended abomasum on the right.

Ultrasound:

• Confirmatory; shows gas-filled viscus with characteristic hyperechoic line and reverberation artifact in an abnormal position

Laboratory:

• Hypocalcemia (total Ca < 2.0 mmol/L)
• Ketosis (BHB > 1.2 mmol/L, positive urine ketones)
• Metabolic alkalosis with paradoxical aciduria (chloride-responsive; hypochloremia)
• Azotemia (prerenal from dehydration)
• Hepatic lipidosis (↑ liver enzymes, bilirubin)

LDA — Surgical (definitive):

• Standing left flank abomasopexy (toggle pin): Minimally invasive; good for LDA; percutaneous placement of toggle pin through abomasum with suture fixation to body wall
• Right paralumbar omentopexy: Open surgical approach; more secure; allows full exploration
• Ventral paramedian abomasopexy: Alternative approach

LDA — Medical (rarely successful alone):

• Casting and rolling (attempt to float abomasum back); low success rate
• Usually reserved for cases where surgery is not possible

RDA / Volvulus:

• Exploratory celiotomy (right flank): De-rotate, assess viability, omentopexy or abomasopexy
• Re-section if necrotic (rare, grave prognosis)

Supportive care (all cases):

• Calcium: IV calcium borogluconate (treat hypocalcemia)
• Ketosis treatment: IV dextrose, propylene glycol PO, corticosteroids (if not pregnant), B vitamins
• Fluids: Correct dehydration and electrolyte abnormalities
• Transfaunation: Rumen fluid transfer to restore microflora
• NSAIDs: Flunixin meglumine for pain and endotoxemia

Prognosis:

• LDA: Good to excellent with surgery (> 85% survival)
• RDA without volvulus: Good with surgery
• RDA with volvulus: Guarded to poor depending on duration and viability