Texas Tech researcher says brisket disease is more than a high-altitude problem
A producer went out and checked his calves. One of the calves was lethargic, had labored breathing, weight loss, droopy ears and a rough hair coat. The producer was sure the calf was coming down with a respiratory virus or pneumonia and gave the calf some medication.
Two weeks later, the producer finds the calf dead. This producer assumes the calf died from pneumonia so he doesn’t have it necropsied. But, according to Joe Neary, who is a professor with the Department of Animal and Food Sciences at Texas Tech University, this calf showed classical symptoms of brisket disease or congenital heart failure.
More than high altitude
Once called high altitude disease, Neary wants producers to know that brisket disease or congenital heart failure is not unique to high altitudes.
“Brisket disease is not high altitude disease,” he states. “Historically, it was only found at altitudes over 7,000 feet, but that is no longer true,” he says. “We are seeing more and more brisket disease at lower altitudes all the time.”
Congenital heart failure is becoming an increasing problem.
“We know this for sure in the feedlot industry, and since the cow/calf sector parallels the feedlot industry, it is likely occurring there, too,” Neary says.
Because the disease is hard to diagnose, Neary encourages producers to take a closer look at their sick cattle.
“A calf may present signs of chronic pneumonia, but it may have brisket disease because they present the same,” he says.
The only visible symptom that is directly related to brisket disease is the distention and pulsation of the jugular vein.
“I would encourage producers to talk to their veterinarian about how to do a necropsy. It may turn out to be brisket disease that has gone undiagnosed for several years,” Neary says.
Cattle can have congenital heart failure from birth.
Brisket disease is initiated outside the heart, starting in the pulmonary vessels. It passes through the right side of the heart, through the pulmonary vessels to the left side of the heart, eventually affecting the whole heart.
Low levels of oxygen cause the pulmonary artery to contract causing the acute, rapid response all animals have when they are at a high altitude.
If low oxygen remains, arteries thicken and contract down. Resistance increases, pressure increases, and the right side of the heart works harder to pump blood.
Eventually, the blood backs up in the venous circulation causing a congestion of blood to increase in pressure in the venous blood. This causes water to move from the bloodstream into the tissues causing swelling in the brisket, under jaw, abdomen, chest and around the heart.
Not all animals present the same way, so swelling may only be present in some areas.
If a calf with brisket disease is necropsied, water can be seen in the brisket region, the liver will appear mottled from the cells dying off, and fluid will be present in the sack around the heart.
Since pulmonary arterial pressure (PAP) is a moderately to highly heritable trait, breeding stock can be screened to identify animals most susceptible to low levels of oxygen.
“Those animals should be identified and removed from the herd,” Neary says.
The PAP test involves putting a large-gauge needle into the jugular vein and feeding a catheter through the jugular vein, through the right atrium, through the right ventricle, up into the pulmonary artery. PAP is measured at that point.
A couple years ago, Neary says 58 calves were PAP tested at three-months of age at a ranch at 9,000 feet. Of these 58 calves, seven died between three and seven months of age from brisket disease.
“All of the calves were healthy at the time of testing,” he says.
Since brisket disease is a moderately heritable trait, selecting on PAP should reduce the incidence of brisket disease in the calf crop, Neary says.
In a study of 1.6 million feedlot cattle in Canada and the U.S., only three in every 10,000 cattle died from this disease in 2000, five times more calves than died from digestive disorders at that time.
However, eight years later, the incidence of brisket disease had doubled in feedlot cattle.
Neary says calves need to be screened at the cow/calf level, and those that have high PAP scores need to be managed differently.
“Brisket disease is not high-altitude disease. It can occur at 2,000 feet or at 9,000 feet,” he states.
The disease isn’t just a problem in the beef industry. Neary says brisket disease is also occurring in Holstein dairy heifers.
“It is the second leading cause of death, after pneumonia, in cows under 1.5 years of age,” he explains.
Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to email@example.com.