Reduce the risk of BVD with biosecurity
Monday, March 4, 2019
Posted by: Joanna Guza, digital communications manager
By Richard Wallace DVM, MS, senior manager, dairy technical services, Zoetis
Bovine viral diarrhea (BVD) is a highly contagious viral disease that can be transmitted as easily as the common cold. It can be spread through direct contact with infected animals, or indirectly by contaminated surfaces or equipment.
Though vaccines have been proven successful for BVD prevention, the in-crease of interstate travel and movement of calves and heifers between dairy operations and calf-and-heifer growing facilities make this costly disease a continued threat to dairies. The most common way that BVD is introduced to herds is through the addition of cattle. (1)
To minimize exposure to BVD, you need to push beyond vaccination protocols as your only line of defense. Test your cattle for BVD, and be aware of its potential presence in your herd. If BVD is present in your herd, focus efforts on identifying infected animals and eliminating them from the herd.
If BVD is not present, your utmost priority becomes keeping the virus out and minimizing losses if it is accidentally introduced. This is where biosecurity measures make a difference.
These five steps are important to developing biosecurity as a portion of a BVD control plan:
- Avoid introducing new animals to your herd unless they’ve been tested. Newly purchased cattle should be screened for BVD and isolated from the herd until results are available. If pregnant animals are purchased, the fetus must be tested after birth for persistently infected (PI) status. Think of new animals like the story of the Trojan horse — a new animal brought into the herd can introduce PI calves into that population. Newly acquired cattle that are pregnant may test negative for BVD, but their unborn fetus may be PI. (1)
- Isolate sick animals from healthy animals. All bodily secretions from cattle persistently infected with BVD will contain virus particles. (1) Bloodborne transmission is possible between PI animals and susceptible contacts through contaminated equipment.
- Give special attention to young animals. Separate calves based on age and management needs, and maintain appropriate animal density so as not to overcrowd. It’s also important to avoid airflow passage from older animals to younger animals. In addition, prioritize disease prevention protocols for calves, including:
- Timely feeding high-quality colostrum or whole milk collected from healthy, confirmed BVD-free cows
- Restricting contact with other calves and older animals in the herd
- Thoroughly cleaning and san-itizing all calf equipment after every use
- Maintaining clean, well-bedded hutches and pens
- Handling sick calves last to avoid transmitting the disease
- Take precautions with visitors and suppliers who might be potential contamination sources. Place hand sanitation and boot sanitation stations, or sanitary foot baths, throughout the dairy and office areas. Prohibit outside vehicles from entering barns.
- Limit interaction with animals from outside your operation. Contact with cattle of unknown backgrounds, such as cattle exhibited at fairs or neighboring cattle with shared fencelines, should also be considered a risk. This also includes exposure to wildlife.
Biosecurity is an essential component of any plan that can greatly reduce exposure to BVD. Identify risks, understand impacts and set a course, alongside vaccination and testing/rem-oval, to protect herds.
To learn more about opportunities for effective biosecurity specific to your dairy, contact your Zoetis representative. DBA and Zoetis will hosted a webinar on the topic of biosecurity. Contact Joanna Guza to get a copy of the webinar.
(1) Grooms D, Givens D, Sanderson M, White B, Grotelueschen D. Integrated BVD control plans for beef operations. Paper presented at 4th U.S. BVDV Symposium; January 27, 2009; Phoenix, Arizona.