Calves are at risk for respiratory disease in the summer months

When calving season finally ends, producers tend to rest a little easier. Through this typically uneventful period of time, it’s important to be on the lookout for pneumonia in calves.

Bovine respiratory disease (BRD) and is often more commonly referred to as shipping fever, summer pneumonia or dust pneumonia. BRD may be caused by either bacterial or viral agents, as well as some additional factors, like stress.

“Contributors to stress play a major role in illness rates and can be related to dust, transporting, weaning, handling, commingling with infected animals, overcrowding, dehorning, castrating and poor nutrition,” Dr. Jeremy Powell, veterinarian and Professor at the University of Arkansas, said.

Research indicates that two patterns have emerged. The first is in very young calves roughly 1 month of age or less. These calves were more susceptible, possibly because of poor colostrum quality or quantity as a result of poor nutrition in the cows prior to calving or drought-like conditions.

The second is when calves were more susceptible was at the 90- to 120-day range. Typically at this time, colostral protection is running out, which is thought to be the increased risk at this stage.

Early detection is key. Calves may exhibit general weakness, lethargy, head down, ears down, poor appetite (decreased interest in coming to the feed bunk, gaunt in the left flank area), respiratory signs (nasal discharge, rapid breathing, extended neck, soft cough) and a fever of greater than 104 degrees.

“These are the most critical symptoms that should be noted to successfully begin early detection of this disease,” Powell said. “Once sights are detected, antibiotic therapy should begin.”

Calves may not exhibit all of these symptoms. It is possible to have livestock at risk for summer pneumonia that do not exhibit respiratory signs early on. Be conscientious of all of these symptoms when checking livestock.

Most animals that have a healthy immune system can successfully fight off a viral infection. However, cattle with immune suppression due to stressful factors can longer hold viral agents in check.

“At that point, they enter the respiratory tract and begin to impair the protective barriers of the normal trachea and lungs,” Powell said. “With the protective barriers gone, bacterial agents are allows to access and infect the respiratory tract. These bacteria can flourish after an initial viral infection or stress factors have weakened the animal’s immunity.”

Prevention and early detection are the key pieces here. Prevention should first focus on minimizing stress factors in your calves. The less an animal is exposed to any of the stress factors, the easier it will be for them to maintain a healthy immune system that could suppress viral or bacteria infections. The other important piece in prevention is vaccination. A veterinarian can decide which vaccines are best suited for a herd.

Producers who suspect pneumonia should consult their veterinarian to assist with establishing an antibiotic treatment course.

“For each sick calf, a treatment record should be prepared that includes the date, calf number, the clinical illness score and the antibiotic treatment administered,” Powell said.

Record keeping allows for tracking treatment expenses and provides for a better compliance with drug withdrawal periods. Delayed treatment will put your livestock at risk for death and will increase the number of chronically infected animals in the herd.

Summer pneumonia can progress and cause severe lung damage that may potentially be irreversible.


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