BRISKET DISEASE: Research Continues
It goes by several names, but the outcome is the same in every instance: it’s fatal. Bovine congestive heart failure, bovine pulmonary hypertension (right heart failure) and brisket disease are one and the same. It’s commonly called brisket disease because of the enlargement of the brisket area with fluid. Cattle will also develop fluid filled pouches under their jaw, abdominal swelling, jugular vein distension with visible pulsation, bugged eyes, and exhale “grunt” with some frothing at the mouth, depression, droopy ears, intermittent watery diarrhea, racing heart, and open-mouth breathing. All this leads to weight loss as the disease progresses. Not all cattle develop all symptoms, but they all die as a result of the disease.
Upon necropsy, brisket disease cattle will have an enlarged heart that has remodeled until is often twice the size of a normal heart, and unable to pump blood and oxygen to the animal. Some cattle die very quickly of brisket disease, others linger for weeks.
According to one study, as early as 1963 brisket disease was reported in cattle grazing at high altitude, with a prevalence of 2-10 percent. In 1976, a similar condition was being reported in yearling feedlot cattle at lower altitudes of 3,000 feet.
Brisket disease is initially challenging to diagnose as it has so many similarities to respiratory problems. Due to the difficult diagnosis and usual treatment for respiratory disease, the animal is not salvageable when it’s determined that it has brisket disease. Even if they haven’t received antibiotics, handling the cattle so that they can be salvaged at all is nearly impossible due to stress/movement-induced heart failure.
Some affected producers in the western plains states have experienced greater losses from brisket disease than bovine respiratory disease, so reducing the impact of brisket disease is a high priority in the industry. Research is currently underway at Great Plains Veterinary Education Center in Clay Center, Nebraska. Brian VanderLey, GPVEC researcher, says “We think that low-altitude and high-altitude cases are a little different. In the last half decade or so, one of the producers said that they’d always seen a few of them but in about 2007 it really came on with more cases. The effort to figure this out intensified and in 2017 we started collecting samples as part of a genetic investigation,” says VanderLey. “We made 21 trips to the Panhandle in about 11 months as we had a case control study going on in several feedlots. The feedlot would identify a case due to clinical signs and we would study the live animal before euthanasia. Then a control animal was chosen to compare it to. In some cases we were able to match half siblings due to the rancher’s sire tag numbers. The premise is to match them as close as possible except for the disease and we matched 102 cases in control.”
“The study included 95 black, five reds, and two red-white faces. Of course, the population with the most cases was black cattle, but it’s important to point out that the feedlot population is predominately black Angus. With the dominance of the black cattle, there was just nothing there that was a standout conclusion,” according to VanderLey.
“I think the black Angus has been hit hard by many for being responsible for this, but I’m not going to go that far. The fact is, the population is predominately black cattle. We have some very promising results that should be out in the near future that will really clarify the genetic factor in the disease,” says VanderLey. “Another thing that people have suggested is the speed at which we grow cattle may be part of the problem. I think that is true of cattle that are already at a genetic risk, but if they already are, maybe they develop the heart failure more quickly as well. There’s a relatively small percentage of cattle that are affected, so backing up the whole pen of cattle to protect the few puts the whole cost of production in jeopardy.”
VanderLey explains “If those cattle at risk can be identified we have a host of options available. Maybe those cattle would be better off fed slower, fed in a different environment, or simply slaughtered off of grass. That’s why figuring out a diagnostic method is so important in our research.”
High altitude producers have been utilizing a test that was developed in the 1960s to determine arterial pressure in the bovine heart. The PAP test used today was developed by Dr. Tim Holt, Colorado State University, Fort Collins, Colorado. It is Pulmonary Arterial Pressure testing and is generally done on yearling breeding bulls and heifers. Some high-altitude registered breeders have utilized the test for quite a few years and are able to more accurately predict which cattle can work at high altitude and which cannot, as it is a highly heritable trait. It’s important to note that PAP testing must be done on the cattle at the altitude they will be inhabiting after they have been at that elevation for at least three weeks.
The research being done to find an earlier diagnosis, and more critically, a way to eliminate the disease from the population in general, is hopefully looming on the horizon for producers and feedlot operators alike.