Displaced Abomasum

What is Displaced Abomasum?

A Displaced Abomasum (DA) is a condition where the abomasum — the fourth and "true" stomach of the cow — shifts from its normal position on the abdominal floor to either the left side (LDA, more common) or right side (RDA) of the abdomen. This displacement traps gas in the abomasum, causing it to fill with fluid and gas, leading to partial or complete obstruction.

DA most commonly occurs in the first 2–3 weeks after calving (fresh period) when the cow is in negative energy balance. Risk factors include: ketosis, high production, over-conditioning at calving (BCS >7), low dry matter intake, and any condition that reduces rumen fill. LDA is 5–10 times more common than RDA.

Clinical signs of LDA: reduced appetite (especially for grain), reduced milk production, decreased rumen motility, ketosis, and the characteristic "ping" sound on auscultation of the left flank. RDA presents more acutely with signs of acute abdomen and may be fatal without prompt surgical intervention.

Treatment options include: surgical correction (toggle pin, right flank omentopexy, left flank omentopexy), roll and trocar (temporary fix for LDA), and milk production response to treatment. The prognosis is generally good with surgical correction, but the underlying causes (ketosis, negative energy balance) must also be addressed to prevent recurrence.

LDA vs RDA

LDA (Left Displaced Abomasum) is the most common form, occurring 5–10 times more frequently than RDA. The abomasum shifts to the left side between the rumen and body wall, trapping gas and fluid. LDA presents with chronic, non-specific signs: reduced appetite (especially for grain), decreased milk production (5–15 lbs/day), ketosis (often positive milk ketone test), and the characteristic "ping" sound on auscultation of the left flank between ribs 9–13. RDA (Right Displaced Abomasum) is more acute and dangerous — the abomasum shifts to the right side, causing right flank distension, acute anorexia, and signs of abdominal pain. RDA may progress to volvulus (twisting), which is fatal without immediate surgical intervention. RDA requires emergency surgery, while LDA can often wait 24–48 hours. Cows with RDA have a worse prognosis than LDA — approximately 70–80% recovery with LDA surgery vs 50–60% with RDA.

DA Diagnosis

Auscultation for ping is the primary diagnostic tool for LDA — listen on the left flank between ribs 9–13 while simultaneously flicking (ballottement) the right flank. A resonant ping indicates gas trapped between the rumen and abomasum. For RDA, auscultate the right flank for gurgling sounds. Milk ketone test is almost always positive with DA (due to associated ketosis). Rumen motility is typically reduced — assess by listening for rumen contractions (should be 1–2 per minute; less suggests a problem). Rectal palpation may reveal a distended rumen or displaced organ. Ultrasound can confirm DA with high accuracy. Combination of reduced appetite, decreased milk, positive ketone test, and ping on auscultation is diagnostic for LDA in >95% of cases. Early detection improves surgical outcomes — cows diagnosed within 3–5 days of onset have better recovery rates than those diagnosed after 7+ days.

Surgical Options

Toggle pin (percutaneous abomasopexy): a minimally invasive procedure performed through a small incision on the left flank under local anesthesia. Quick (15–30 minutes), low cost ($100–$200), but higher recurrence rate (5–10%). Best for simple LDA cases in otherwise healthy cows. Right flank omentopexy: the most common surgical approach for both LDA and RDA. A 6–8 inch incision on the right flank, the abomasum is repositioned and sutured to the body wall. Cost: $300–$500 including anesthesia. Recovery time: 2–4 weeks. Success rate: 85–95%. Left flank omentopexy: similar approach from the left side, slightly less common due to access difficulties. Roll and trocar: a temporary fix for LDA where the cow is rolled onto her right side and a trocar (large needle) is inserted through the left flank to release gas. Cost: $50–$100, but recurrence is common (20–30%). Consider it a stabilizing measure until a veterinarian can perform definitive surgery. Choose the surgical option based on cow value, herd size, and available veterinary support. For high-value cows, right flank omentopexy provides the best long-term outcome.