For as long as anyone can remember, pork producers have vaccinated gilts for parvovirus. Now that outbreaks are rare, is it necessary to vaccinate the entire breeding herd?
“We still need to vaccinate [sow herds] for parvovirus,” insisted Noel Garbes, DVM, a technical services veterinarian at Zoetis.
“It is still around and can remain infectious in the environment for an extended period of time.”
What’s different today, he told Pig Health Today, is the virus is no longer endemic in some herd. Unvaccinated sows therefore do not develop immunity from natural exposure. Without natural exposure, a failure in vaccination protocols could cause problems if parvovirus is introduced.
“If you bring in some positive gilts and you’re not vaccinating the sow herd, you could have a lot of reproductive failure issues,” Garbes told Pig Health Today.
“Reproductive failure characteristics we see with parvovirus are the same that we see with other viruses like porcine reproductive and respiratory syndrome. It becomes a very complicated web to figure out what the problem is on a farm,” he explained.
A few of the symptoms are stillborns, mummies, embryonic deaths and infertility issues.
Properly administering vaccines
Proper vaccine protocol is always important for gilts to be protected against parvovirus and other diseases. Caregivers need to understand the required procedures including “warming up the vaccines, taking care of vaccines and giving them properly,” Garbes said.
When a parvovirus vaccination program goes wrong, it often shows up as mummies in gilts.
“We have to go back and look at maternal immunity on those incoming replacement gilts,” Garbes said. “When did we give the vaccine? Was it given properly? And proper timing because we know that maternal antibodies can last out maybe 24 to 26 weeks. If we vaccinated gilts early, that first vaccine may be blocked a little by maternal-derived antibody.”
Sows infected with parvovirus do not show clinical signs. Instead, the sows will have “maybe a low live-born, or maybe they’re not pregnant at all,” he continued. “They check positive but all at once, they don’t have any pigs. They don’t farrow. So basically, we’ve got less pigs to sell.”