We’ve chatted before about the amazing digestive system of the ruminant. With four stomachs, these animals are the ultimate digesters of grass and other plant material, getting their energy not from the food they eat but rather the by-products of the microbes within their guts. Not surprisingly, for a system so uniquely evolved, there are times when things go wrong. But what may surprise you is how we fix these things on the farm.
To begin, there is a specific condition in bovines called an LDA, which stands for left displaced abomasum, more commonly referred to as a twisted stomach, or simply, "a twist." If you’ll recall, the abomasum is the fourth stomach of the ruminant and is considered the "true stomach," meaning it is the compartment that has the standard acidic gastric juices and digestive enzymes that we monogastric animals solely depend on.
Sometimes, this organ becomes filled with gas. This is most commonly seen in dairy cows within a month of calving. During this period of a dairy cow’s life, she is undergoing huge metabolic changes and is susceptible to many different problems if her diet and health are not managed very carefully. Mastitis (inflammation and infection in the udder), metritis (inflammation and infection in the uterus), metabolic ketosis, and low calcium are the most commonly encountered problems in the recently "freshened" cow as she switches from being a a non-lactating pregnant animal to a heavily lactating, non-pregnant animal. Any of these problems contribute to hypomotility within the gut, which leads to excessive gas accumulation.
As gas accumulates within the abomasum, it begins to float around within the abdominal cavity. Normally, this organ lays quite happily on the bottom right of the abdomen, close to the rib cage, loosely attached to abdominal fat called the omentum. When filled with gas, however, it acts like a balloon and rises to the upper left quadrant, then stubbornly stays there as the gas becomes trapped.
As you can imagine, this doesn’t bode well for the cow. With her digestive system not moving things forward and making her feel like a blimp, she stops eating and stops producing milk. Decreased milk production is usually the very first sign of an LDA and many experienced dairy farmers suspect with great accuracy this diagnosis even before they call me.
The most fun thing about LDAs is the diagnosis: you ping the cow. This means you stand on the left of the cow and press your stethoscope along the last rib. Then you flick her side with your fingers. If there is an LDA, you will hear a sound like a basketball hitting a concrete floor; a "ping." This is the gas reverberating within the abomasum. If you get a ping, you’ve got an LDA. Then it’s time to go to work.
There are a few ways to fix an LDA. I’ll tell you the way I do it. It’s an abdominal surgical procedure called a right flank pyloric omentopexy. With the cow standing in a chute, a vertical incision about eight inches long is made into the right flank after the skin has been scrubbed and numbed with a local anesthetic. Then, I reach into the abdominal cavity all the way up to my armpit (trying not to fall into the cow), stretching past intestine, rumen, and liver, up the left side where the rouge abomasum is hanging out. I then take a tube with a needle at the end and stick the abomasum to drain off the gas, which causes the organ to slowly sink.
After the gas is released, I remove the needle and tube and then reach under the cow from the right side, tugging at the omentum to pull the abomasum back to the right side where it belongs. Once it’s been pulled back, I stitch the omentum to the lining of the abdominal cavity, called the peritoneum. Then I close the hole that I made and we’re finished.
My first LDA surgery took two hours and I was exhausted. My arms were sore, I had blood running down my side, and I kept sticking myself with the gigantic needle as I sewed up the cow’s flank. Afterwards, my boss commented somewhat sardonically that I needed to get my time under one hour. After a few more under my belt, I actually did.
The biggest thing that strikes me with these cases of twisted stomachs is how well the cows do. During the surgery, they usually just stand there as I’m swishing my arm around their insides — the most painful part is the flank incision and that part is numbed! After the surgery, pending no other complications, they usually begin eating within twelve hours.
Are you kidding me? A twelve-hour recovery time after abdominal surgery with the likes of me fiddling around in there while I discuss where to get the best lemon meringue pie with the dairy farmer? Now that’s impressive.
Dr. Anna O’Brien