Right Displaced Abomasum (RDA) in Cows: Symptoms and Treatment Options

Right displaced abomasum, or RDA, is a condition where the cow's abomasum moves from its normal position on the lower abdomen into the upper right side of the belly. The abomasum is the cow's "true stomach," and when it becomes distended with gas and fluid, it can shift out of place.

This matters because RDA is not only a displacement problem. In some cows, the abomasum can rotate or twist, leading to abomasal volvulus. That twist can reduce blood flow, trap fluid, and cause rapid dehydration and shock. Because early RDA and early volvulus can look similar, your vet usually treats suspected RDA as a time-sensitive condition.

RDA is seen most often in adult dairy cows around calving and early lactation, especially when feed intake is off or another fresh-cow illness is present. While left displaced abomasum is more common overall, right-sided displacement is usually more urgent because of the risk of progression to volvulus.

RDA is considered multifactorial, meaning several things usually come together. The main problem is reduced abomasal motility, also called hypomotility. When the abomasum is not emptying normally, gas and fluid build up, making it easier for the organ to float and shift to the right.

Risk is highest in the periparturient period, especially during the first month after calving. Fresh cows often have changes in abdominal organ position, fluctuating feed intake, and metabolic stress. Conditions that commonly increase risk include ketosis, hypocalcemia, hypokalemia, metritis, mastitis, and reduced rumen fill.

Diet also matters. High-concentrate, low-roughage feeding, abrupt ration changes, and poor transition-cow intake can all contribute. Deep-bodied, high-producing dairy cows appear to be at greater risk as well. In many herds, RDA is part of a broader fresh-cow management picture rather than a one-time random event.

Your vet usually starts with a physical exam, herd history, and the cow's stage of lactation. The classic finding is a high-pitched ping on the right side during simultaneous percussion and auscultation of the abdomen. Your vet may also hear fluid-splashing sounds and assess rumen fill, hydration, manure output, and heart rate.

Because other right-sided abdominal problems can also create a ping, diagnosis involves ruling out conditions such as cecal dilation, intestinal disease, or abomasal volvulus. Rectal examination may help, although the abomasum is only sometimes reachable in uncomplicated RDA and is more likely to be palpable when severe distension or volvulus is present.

Lab work can support the diagnosis and help guide treatment. Cows with RDA often have hypochloremic, hypokalemic metabolic alkalosis, and some also have ketosis or low calcium. Ultrasound may help confirm displacement, but it does not always reliably separate RDA from volvulus. Because that distinction can be difficult before surgery, your vet may recommend prompt surgical correction when RDA is suspected.

Prevention focuses on fresh-cow and transition-cow management. The goal is to keep cows eating well, maintain rumen fill, and reduce the metabolic problems that slow abomasal motility. Good dry-cow nutrition, a well-balanced transition ration, and avoiding abrupt feed changes are central steps.

Adequate effective fiber and roughage matter. Herds can often lower displaced abomasum risk by supporting a rapid return to rumen volume after calving and by using a total mixed ration rather than large grain meals fed separately. Consistent bunk access, minimizing overcrowding, and reducing heat or social stress can also help support intake.

Work with your vet and nutritionist to reduce ketosis, hypocalcemia, metritis, mastitis, and other fresh-cow illnesses, because these conditions often travel with displaced abomasum. Tracking fresh-cow appetite, milk drop, manure output, and rumen fill can help your team catch problems early before a displacement becomes a crisis.