Bovine Respiratory Syncytial Virus in Cattle: BRSV Symptoms and Care
- See your vet immediately if a calf or adult cow has labored breathing, open-mouth breathing, blue or gray gums, marked depression, or stops eating.
- Bovine respiratory syncytial virus, or BRSV, is a contagious viral cause of pneumonia and is a major part of the bovine respiratory disease complex.
- Common signs include fever, cough, nasal discharge, fast breathing, reduced appetite, and a sudden drop in energy. Some cattle worsen quickly.
- There is no direct antiviral treatment routinely used in cattle, so care focuses on supportive treatment, anti-inflammatory medication, and managing secondary bacterial pneumonia when your vet suspects it.
- Typical on-farm cost range is about $150-$600 per animal for exam, medications, and basic supportive care. Severe cases needing repeated visits, diagnostics, or hospitalization can reach $800-$2,500+ per animal.
What Is Bovine Respiratory Syncytial Virus in Cattle?
Bovine respiratory syncytial virus, usually called BRSV, is a contagious virus that infects the airways and lungs of cattle. It is one of the important viral triggers in the bovine respiratory disease complex, especially in calves and recently stressed groups. Outbreaks can move through a herd quickly, and some animals develop severe pneumonia or sudden breathing distress.
BRSV damages the lining of the respiratory tract and can make it easier for bacteria such as Mannheimia haemolytica and Pasteurella multocida to move in afterward. That means a viral infection can turn into a mixed viral-bacterial pneumonia problem. In field cases, cattle may range from mildly affected to critically ill within a short time.
Young calves are often hit hardest, but older cattle can also become sick. Stress from transport, weaning, commingling, crowding, poor ventilation, and abrupt weather changes can raise the risk of disease and make outbreaks more severe.
Because BRSV can look like other causes of cattle pneumonia, your vet usually considers it part of a bigger respiratory picture rather than a stand-alone diagnosis.
Symptoms of Bovine Respiratory Syncytial Virus in Cattle
- Fever
- Cough
- Fast breathing
- Labored breathing or open-mouth breathing
- Nasal discharge
- Reduced appetite or not coming to feed
- Depression or lethargy
- Abnormal lung sounds
Mild cases can look like a routine respiratory infection at first, but BRSV can worsen fast. Worry more if breathing becomes visibly harder, the animal stretches its neck to breathe, stands with elbows out, will not rise, or stops nursing or eating.
See your vet immediately for severe breathing effort, open-mouth breathing, collapse, or sudden deaths in a group. Those signs can mean advanced pneumonia, low oxygen, or a secondary bacterial complication.
What Causes Bovine Respiratory Syncytial Virus in Cattle?
BRSV is caused by infection with bovine respiratory syncytial virus, a respiratory virus spread mainly through close contact, respiratory secretions, and contaminated people, equipment, or housing areas moving between groups. Once it enters a herd, it can spread quickly, especially where cattle are housed close together.
The virus is most likely to cause trouble when cattle are already under stress. Common risk factors include weaning, transport, sale-barn exposure, mixing cattle from different sources, overcrowding, dust, damp bedding, and poor airflow. These stressors weaken normal airway defenses and make infection more likely.
BRSV also matters because it can set the stage for secondary bacterial pneumonia. After the virus injures the respiratory lining, bacteria that may already be present in the upper airway can move deeper into the lungs. That is one reason some cattle become much sicker than others in the same outbreak.
Not every coughing calf has BRSV. Other viruses, bacteria, lungworms, and noninfectious lung problems can look similar, so your vet may recommend testing to sort out the cause and guide herd-level decisions.
How Is Bovine Respiratory Syncytial Virus in Cattle Diagnosed?
Your vet starts with the history and physical exam. Important clues include fever, cough, increased breathing effort, recent transport or weaning, and multiple cattle getting sick around the same time. Lung sounds, hydration, and oxygenation help your vet judge how serious the case is.
Because BRSV overlaps with other causes of bovine respiratory disease, diagnosis often includes testing. Veterinary diagnostic labs commonly use PCR on nasal or deep nasopharyngeal swabs, transtracheal wash, bronchoalveolar lavage fluid, or fresh lung tissue. In some labs, BRSV is included in a broader bovine viral respiratory PCR panel.
Your vet may also recommend additional tests to look for mixed infections or complications, such as bacterial culture, necropsy of animals that died, or herd-level outbreak workups. In field practice, treatment may begin before test results return if cattle are clearly ill.
A practical cost range for diagnosis is about $150-$500 per animal for an exam plus basic testing, with herd investigations or multiple lab submissions increasing that total. Stand-alone respiratory PCR testing at U.S. veterinary diagnostic labs often falls around $35-$112, not including sample collection, shipping, farm call, or interpretation.
Treatment Options for Bovine Respiratory Syncytial Virus in Cattle
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm exam by your vet
- Temperature check and respiratory assessment
- Isolation from the group when practical
- Improved ventilation, dry bedding, easy access to water and feed
- Anti-inflammatory medication if your vet recommends it
- Empiric treatment for likely secondary bacterial pneumonia when your vet feels the risk is high
Recommended Standard Treatment
- Farm exam and repeat rechecks
- Targeted supportive care plan from your vet
- Anti-inflammatory medication and hydration support as indicated
- Antimicrobial treatment when secondary bacterial pneumonia is suspected
- Basic diagnostics such as respiratory PCR, bloodwork, or sample submission
- Group management steps for exposed cattle, recordkeeping, and treatment response tracking
Advanced / Critical Care
- Urgent veterinary reassessment or referral-level care
- More intensive monitoring of breathing effort and hydration
- Oxygen support where available
- IV or more aggressive fluid support when appropriate
- Expanded diagnostics such as transtracheal wash, ultrasound, necropsy, or herd outbreak investigation
- Treatment of severe secondary pneumonia and complications under your vet's direction
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Bovine Respiratory Syncytial Virus in Cattle
Bring these questions to your vet appointment to get the most out of your visit.
- Does this look most consistent with BRSV, or are other causes of pneumonia also likely?
- Which cattle should be treated right away, and which ones can be monitored closely?
- Do you suspect secondary bacterial pneumonia in this animal or group?
- Would PCR testing or a respiratory panel change treatment or herd management decisions?
- What signs mean this animal needs emergency reassessment today?
- How should we isolate sick cattle and reduce spread through the rest of the herd?
- What vaccination timing makes sense for our calves, replacements, or incoming cattle?
- What ventilation, stocking density, bedding, or transport changes would lower our future risk?
How to Prevent Bovine Respiratory Syncytial Virus in Cattle
Prevention is a mix of biosecurity, stress reduction, and vaccination planning with your vet. BRSV spreads more easily when cattle are mixed from different sources, transported long distances, or kept in crowded, poorly ventilated spaces. Good airflow, dry bedding, lower dust, and avoiding overcrowding all help support the lungs.
Work with your vet on a herd vaccination program that fits your cattle type, age group, and management system. Respiratory vaccine programs for cattle commonly include BRSV along with other viral pathogens such as IBR, PI3, and BVD. Vaccination can help reduce disease impact, but field protection is not perfect, so management still matters.
Quarantine or closely observe new arrivals before mixing them into the herd. Clean feeding equipment, waterers, and handling areas regularly, and try to limit unnecessary movement of people and tools between sick and healthy groups during an outbreak.
If multiple cattle are coughing or running fevers, early herd-level action matters. Prompt veterinary involvement, accurate records, and testing representative cases can help control losses faster and improve future prevention planning.