Pneumonia in Calves
Don’t forget to manage the predisposing factors that set calves up
to be at risk of pneumonia.
Pneumonia can affect calves of any age. Most pathogens that cause lung infections are already present in the calf’s respiratory tract and become a problem when its immune defenses are compromised by stress. Stress may be due to bad weather, extreme changes in temperature, a long truck haul, overcrowding in a dirty environment, or nutritional stress due to deficiencies of an important mineral such as copper or selenium.
Studies have shown that lung damage from calfhood pneumonia can compromise a calf’s potential for later growth. The damage and scar tissue from severe pneumonia may be permanent.
Mike Apley, head of production medicine and clinical pharmacology at Kansas State University’s College of Veterinary Medicine, says the Texas Ranch-to-Rail program showed that calves with lung lesions at slaughter gained less than those that didn’t have lung lesions.
“It has been well-documented that pneumonia decreases performance. Yet we are not sure how much the pneumonia in a month-old calf will affect his later performance in the feedlot,” he says. It may make a difference how quickly you find and treat a calf — if you treat him before there is extensive damage, or whether damage is severe after a prolonged battle to try to save the calf. Advanced lung damage can be permanent.
“Producers need to consult with their herd health veterinarian to devise the best strategies for their own herds,” says Apley. “This past year, in talking with veterinarians, we were seeing the same thing we’ve seen in some other years: sickness even in well-vaccinated herds with good nutrition and management and preweaning vaccinations. We saw some outbreaks in some calves 30 to 60 days postweaning. Even with good management and proper vaccination programs, this can happen.”
Environmental and other factors may play a role, such as the hot, dry, dusty conditions or respiratory irritation from constantly breathing smoke and ash from the catastrophic fires in the West during the past summer. Dust and/or smoke can overwhelm the cilia in the trachea and compromise the calf’s ability to clear these foreign particles from the respiratory passages. It’s not always a simple issue.
“We tend to chase the bug of the day. We do diagnostics on these calves and find certain organisms and assume these are the culprit. Perhaps a certain type of pathogen is to blame, in a way, but there was a predisposing factor setting it up,” he says.
Editor's Note: Heather Smith Thomas is a freelancer and cattlewoman from Salmon, Idaho.
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