Bovine Viral Diarrhoea (BVD) is a significant viral infection that affects cattle, leading to substantial economic losses in the dairy industry. This blog will delve into the details of BVD, its transmission, signs and symptoms, the importance of testing, prevention strategies, and effective management practices.
What is Bovine Viral Diarrhoea (BVD)?
BVD is a highly contagious viral disease caused by the Bovine Viral Diarrhoea Virus (BVDV). The virus affects cattle of all ages, leading to a range of clinical manifestations, from mild to severe, including respiratory issues, reproductive problems, and immunosuppression. One of the most significant impacts being infection of the unborn calf if a pregnant cow is infected, resulting in the birth of a persistently infected (PI) calf
How is BVD Transmitted Among Dairy Cows?
BVDV is primarily transmitted through direct contact with infected animals. The virus can be spread via saliva, nasal discharge, urine, and feces. Additionally, vertical transmission can occur from a pregnant cow to her fetus, leading to persistently infected (PI) calves.
Signs and Symptoms of BVD in Cattle
Symptoms of BVD vary based on the strain of the virus and the age of the affected animal. Common signs include fever, diarrhea, respiratory distress, nasal discharge, and reduced milk production. In pregnant cows, BVD can cause abortions, stillbirths, and congenital defects.
Why is BVD Testing Important for My Dairy Herd?
BVD testing is crucial for identifying infected animals and managing the disease effectively. Early detection helps prevent the spread of the virus within the herd, safeguarding the health and productivity of your cattle.
How is BVD Transmitted Among Dairy Cows?
- Real-time PCR – This method detects the viral RNA and is highly sensitive and specific.
- Antibody Detection (ELISA Tests) – These tests identify antibodies against BVDV, indicating exposure to the virus.
- Virus Isolation – This traditional method involves growing the virus from samples in a lab setting.
How Can I Prevent BVD in My Dairy Farm?
Preventing BVD involves a combination of biosecurity measures, regular testing, and vaccination. Implementing strict biosecurity protocols can minimise the risk of introducing the virus to your herd. Regular testing helps identify and manage infected animals pro
Steps to Take if BVD is Detected in Your Herd
If BVD is detected, it is essential to isolate infected animals and follow a comprehensive disease management plan. Work closely with a veterinary professional practitioner to develop a strategy that includes culling PI animals, vaccinating the herd, and enhancing biosecurity measures. In Ireland BVD is a notifiable disease, and outbreaks should be managed as set out under the Animal Health Ireland BVD eradication programme.
Impact of BVD on Milk Production in Dairy Cows
Although BVD does not directly impact milk production, the overall health issues caused by the virus, such as immunosuppression and secondary infections, can lead to decreased milk yield and quality.
Effective Vaccines for BVD in Cattle
Vaccination is a key component of BVD prevention. Several effective vaccines are available that can protect your herd from BVDV. Consult with your veterinarian to choose the most suitable vaccine for your farm.
Best Practices for Managing BVD in Dairy Herds
- Regular Testing
- Conduct routine BVD testing to monitor the health status of your herd. All newborn calves should be tested using “Ear notch testing” , by taking a sample from the calf’s ear when it is tagged.
- Vaccination
- Implement a comprehensive vaccination program.
- Biosecurity
- Enforce strict biosecurity measures to prevent the introduction and spread of BVDV.
- Record Keeping
- Maintain detailed records of animal health, vaccinations, and test results.
For more information on BVD testing and management, contact FarmLab Diagnostics. Our team of experts is here to help you safeguard your herd’s health and productivity. Contact us today to learn more.