Bovine viral diarrhea virus (BVDV) has been found to survive for a period of time on materials common to livestock operations. In a paper in the Summer 2011 Bovine Practitioner, Elliot Stevens, DVM, PhD, Kansas State University, and others found that a type 1b, noncytopathic BVDV isolate survived longer in two aqueous solutions (water and PBS which simulated mucus), latex, enameled metal and paper. However, BVDV had lower survival rates on galvanized metal and porous material including soil and pine.
Stevens notes that in other studies transmission of BVDV was accomplished through rectal palpation of a PI-BVDV infected heifer followed by palpation of naïve heifers with the same palpation sleeves. Other studies demonstrated BVDV transmission via hypodermic needles and nose tongs.
BVDV in water
For years it has been recommended to clean cattle water tanks for a variety of reasons; pathogen reduction is one of those. This study showed that when BVDV was present in mucus, it was recovered for longer periods of time in water.
“Cleaning water tanks is very important for many reasons including food safety, animal performance and general upkeep of facilities,” says Dan Thomson, DVM, PhD, Kansas State University. “We have not studied pathogen control much in regard to water tanks. It would make sense that water tanks could be an area of concern for spread of contagious pathogens in cattle.” Thomson has seen studies where bleach was used to clean water tanks. “Immediately the tank was free of pathogens (foodborne, viral, etc.). However, 24 hours later the tank was populated again with the bacteria from cattle using the tank.”
Chris Chase, DVM, PhD, South Dakota State University, who was also involved in this study, agrees that it’s important to get tanks clean to help prevent the spread of BVDV. “BVDV is really pretty easy to kill so a mild disinfectant like quaternary ammonium or a very dilute bleach solution would work.” This is even more important in hospital pens and pens where new or naïve calves may share waterers with an adjacent pen of older animals.
“As we move cattle in and out of hospital pens, only to return them to home pens scattered across the yard, these types of biosecurity issues have to be of some concern,” Thomson adds. “The same concern should be made of re turning a sick calf back to its home pen where the healthy calves drink after it. The commingling we see prior to arrival at the feedyard, after arrival to add cattle on to fill home pens, and running cattle through hospitals is probably of more concern than the actual water tanks.”
BVDV in mucus
The study showed a longer survival time of BVDV in mucus. It’s important to remember that mucus is not just located in the water tank. “Mucus could be on the sides of the snake, the chute, the feedbunk, etc.,” Thomson explains. As a result, there are many points of contact that we should be thinking about when it comes to biosecurity, fomites and BVDV in the feedyard. One example is when the same facility is used for processing and doctoring. “Do we power wash the sides of the snake and chute between groups?” Thomson asks. “There is a lot of research to be done in this area.”
Stevens adds that it was very interesting to see the impact of the mucus on BVDV survival. “Depending on the time of the year it would be interesting to think about the impact of the ambient air temperature on survival in the water tanks,” he says. “Additionally, there are other viruses that could be evaluated, which may be impacted by mucus.”
BVDV on other materials
BVDV was also found to survive longer on latex. “The latex gloves worn by our crews are more to protect our crews than it is to provide a cleaner environment for administering our products,” Thomson says. “I don’t think this is a big issue as most latex gloves are thrown away periodically throughout the day.”
Studies on BVDV in the environment indicate that it lasts in the soil and in a pen for less than four days. “Researchers have shown that BVDV seronegative calves can pick up BVDV from exposure in a pen when a persistently-infected BVDV animal has been removed from it only four hours prior to introducing the naïve cattle,” Thomson says. However, if the pen was allowed to be vacant for four days, the naïve cattle did not pick up BVD virus from the environment.
“I think this study is a great start to learning about biosecurity in feedlot cattle,” Thomson states. “BVDV is a virus of interest and we still have a lot to learn.”