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Pneumonia, or bovine respiratory disease (BRD), is the second-highest cause of mortality in preweaned dairy calves and the highest cause of mortality in post-weaned dairy calves.1
“Sometimes, despite every precaution, calves will still develop BRD,” said Linda Tikofsky, DVM, Boehringer Ingelheim. “When that happens, it is important to have a detection and treatment plan in place to minimize the impact of the disease on your animals and your bottom line.”
Stay alert to identify illness early
Early detection of symptoms and a quick diagnosis are vital to helping calves recover. Some symptoms of BRD to look out for include:
- Fever – early in the course of respiratory disease, a fever is a fairly consistent sign
- Reduced appetite – the animal may be slow to come to eat or lose their appetite completely
- Nasal discharge – discharge will appear watery in the early stages and later may become yellow, white or blood-tinged
- Droopy ears – the animal may appear lethargic and withdrawn from the main herd
- Cough – a cough may or may not be present
“Not all signs of infection are obvious, but both the University of California-Davis and the University of Wisconsin-Madison have developed calf health scoring apps so that you can walk down the row and score calves on a variety of criteria,” explained Dr. Tikofsky. “This makes it easier to notice small changes in an animal’s health.”
Training employees to know the symptoms of BRD and identify calves that are potentially ill also goes a long way toward giving animals the best chance against BRD. Additionally, quarantining animals with a suspected illness prevents the spread of disease when caught early.
Testing and diagnosis determine treatment
Early signs of BRD can be subtle. Your veterinarian can provide a variety of diagnostic tools and services that can help you identify sick calves earlier and more accurately.
“An ultrasound is a great tool for detecting subclinical BRD cases, when producers can’t see visible symptoms, or to evaluate the success of BRD management changes,” said Dr. Tikofsky. “Many veterinarians are trained in how to perform an ultrasound on lungs, and can help identify these BRD cases earlier.”
Routinely scanning lungs may help identify high-risk times for BRD, allowing producers to implement management changes or use targeted metaphylaxis. Metaphylaxis is the administration of a respiratory antibiotic to a group of at-risk calves to reduce sickness and death. Recently, the concept of targeted metaphylaxis, or using metrics to narrow the use of antibiotics from entire groups of cattle to individual high-risk calves with the help of a veterinarian, is gaining popularity.
Another option to enhance treatment and prevention protocols is diagnostic testing to pinpoint the cause of respiratory infections. A pathologist at a diagnostic lab will work with your veterinarian to more closely examine the bacteria or viruses present. This can be done antemortem by obtaining nasal swabs from the calf, or postmortem through a necropsy evaluation.
Choose a swift and effective treatment
Once a calf has been diagnosed and assessed, you can apply the appropriate treatment protocol. Work with your veterinarian to establish and update these protocols over time.
“When treating their herd, producers should look for a broad-spectrum and fast-acting antibiotic that treats the major BRD-causing pathogens,” stated Dr. Tikofsky. “A treatment that reaches the lungs quickly will minimize long-term lung damage.”
Determine appropriate post-treatment interval (PTI)
It can be tough to determine when a sick calf may need another treatment — or if the antibiotic should be allowed a few more days to clear the infection. Talk with your veterinarian about setting an appropriate post-treatment interval (PTI) for your herd. A PTI is the time after a treatment is administered before a re-treatment should be administered.
“It’s also essential to keep accurate records and follow the product label when administering antibiotics,” concluded Dr. Tikofsky. “Over time, records can tell us whether or not the diagnosis, treatment and PTI protocol are effective, or if we need to make changes.”
1 USDA APHIS, Veterinary Services, National Animal Health Monitoring System (NAHMS). Health and management practices on U.S. dairy operations, 2014. Available at: https://www.aphis.usda.gov/animal_health/nahms/dairy/downloads/dairy14/Dairy14_dr_PartIII.pdf.