Disinfectant fogged over pigs kills lingering pathogens

Two lingering cases of porcine epidemic diarrhea (PED) at different finishing units were frustrating Ross Kiehne, veterinarian with Swine Vet Center, St. Peter, Minnesota.

“These barns tested positive to PED before, but these were sites we wanted to use for gilts,” Kiehne explained. “We cleaned up the barns and utilized normal disinfectants. We put gilts back in there, but oral-fluid testing indicated the pigs were positive for PED.

“We didn’t see any clinical signs so we thought it might be an environmental contaminant. But we weren’t going to use the gilts as long as they were testing positive, even if we thought it was a false positive.”

Fogging allowed over pigs

A possible solution was a disinfectant that could safely be fogged into barns with pigs present. Kiehne had heard about preliminary university tests indicating a disinfectant called Zoono Microbe Shield was effective for many diseases on impact plus residual action for at least 7 days.

“It’s a fairly new disinfectant that you can apply right over the pigs,” he said. “I convinced the owner to spray with Zoono. We sprayed and tested multiple times. The pigs tested negative every time, so we were comfortable using those gilts.”

If the product hadn’t worked, Kiehne’s client may not have been able to use the gilts. Or they needed to go through the process of moving the gilts out, cleaning and disinfecting again to try to achieve negative tests.

“What I like about Zoono is it is very safe and can be sprayed with pigs in the barns,” Kiehne said. “And the 7 days of residual action is very significant. All other disinfectants kill on impact only and offer no other action.”

Since the success with clearing PED from the finishers, Kiehne has fogged the disinfectant in rooms with pigs from 3 to 4 days old up to sows, with no adverse effects.

Further testing

“We are trying to utilize this product more now for similar circumstances,” Kiehne said. “I think it was an environmental contaminate that was causing us some headaches with the PED tests. Now I’m going to do more testing over pigs for other diseases.”

In addition, more information on Zoono’s use in swine should be available soon from a study conducted by Derald Holtkamp, DVM, at Iowa State University. Holtkamp is evaluating Zoono and should have results later this summer.

Zoono kills ASF, COVID-19

Zoono’s disinfectant product has been thrust into the limelight the past few years after outbreaks of African swine fever (ASF) and COVID-19 in China. The product developed by Zoono Group Limited, a New Zealand company, kills ASF and COVID-19 on contact and offers residual action up to 30 days for some pathogens, according to information on its website.

Key to the product’s success is the Zoono Microbe Shield that forms a bond with surfaces to inhibit growth of microbes. The EPA-approved product is safe for humans and animals because it uses a technology to kill the microbes without dangerous chemicals.

Companies like United Airlines now use Microbe Shield to provide a layer of protection in the passenger cabins on everything from seats and tray tables to lavatories.

For more information on Zoono, visit www.apiamsolutions.com.



Antibiotics properly timed during PRRS virus outbreak reduce reproductive failure

An outbreak of porcine reproductive and respiratory syndrome (PRRS) on a sow farm will trigger reproductive failure in gestating sows. While PRRS is a viral disease, it causes endometrial inflammation leading to abortions, stillborns and mummified fetuses.

Ross Kiehne, DVM, with Swine Vet Center, conducted a study to evaluate the use of the injectable antimicrobial Draxxin® (tulathromycin) administered to gestating sows during a PRRS virus outbreak. Specifically, he wanted to see how administering the antibiotic at different stages of gestation affected the rate of reproductive failure.

On-farm investigation

The investigation was conducted on a 2,500-sow farm in northeast Iowa that broke with PRRS virus in mid-2019. The first 5-mL dose of Draxxin was administered to gestating sows 5 days after the outbreak was detected. A live viral inoculation (LVI) was performed 2 days later. A second round of the antibiotic was administered 13 days after LVI. About 20% of the sows were not treated, and these animals served as a control.

Data collected for the study was based on the pregnancy stage when the first antibiotic treatment was administered. The gestation stages were day 0-18, day 19-29, day 30-49, day 50-69, day 70-90 and day 91-105.

Kiehne used four reproductive outcomes for analysis: 1) abortions, culls and death; 2) farrowed and found open; 3) preg-check negative; or 4) repeat mating. The number of pigs weaned per sow was also determined for each animal enrolled in the study.

Positive outcomes in later gestation

The study verified Kiehne’s hypothesis that while administering Draxxin during early gestation is detrimental, it is beneficial during later gestation.

“Administering this antibiotic during early pregnancy appears to increase negative outcome events such as found open, preg-check negative and repeat mating,” Kiehne said.

“However, there appears to be an advantage to administering it in a PRRS virus situation after 50 days of gestation,” he continued. “This advantage is apparent in a reduction in abortions, stillborns and mummified fetuses and increase in total pigs weaned.”

Overall, the study found the percentage of sows that farrowed was higher for those given the Draxxin treatment at 68.5% versus 64.1% for the control sows with no antibiotic. Sows with abortions was lower for those receiving the Draxxin treatment at 17.4% versus 22.9% for the control group. Sows not pregnant was 6.9% for those given the Draxxin treatment and 6.7% for the control group. The deads and culls category was 7.2% for sows receiving the Draxxin treatment and 6.3% for the control group.

Weaned pigs per enrolled sow was calculated in each pregnancy group. In the early pregnancy stages, weaned pig averages were lower for sows receiving the Draxxin treatment compared to controls. After day 50 of gestation, the number of weaned pigs increased for sows receiving the Draxxin treatment compared to the control group.

In conclusion, Kiehne recommends administering the injectable antimicrobial Draxxin to sows after day 50 of gestation during a PRRS virus outbreak. However, administering it any earlier would be detrimental.



People in pork production just as important as pigs


While their schooling focused on pigs, veterinarians on the job spend a lot of time working with clients and members of their staff. After all, they must carry out a veterinarian’s health or production plan for the pigs.

“Our whole training in veterinary school is about the pigs, and we don’t spend a lot of time on the people,” reported Ross Kiehne, DVM, Swine Vet Center, St. Peter, Minnesota.

“We just kind of put the plan together and away we go. Then we might come back and wonder why it didn’t work…And not understand that there’s human reasons why it didn’t work out, not pig reasons.”

Stressful situations

Workers in hog barns generally want to see pigs do well, but difficult situations with the animals can lead to a breakdown in care.

“Some diseases are very devastating,” Kiehne said. “Sow death loss, for example, is really hard to watch.”

Veterinarians as well as clients should watch for signs of stress among staff. Kiehne said he sees some workers who exhibit their stress right away and then appear to get over it. But there are others who don’t show their stress and become quiet and introverted. These people may need to discuss the situation with someone else who understands such as a veterinarian or co-worker.

Veterinarian stress

Veterinarians aren’t immune to stress either. Kiehne said he’s seen colleagues experience great stress and family hardship. His response was to help pick up their work.

Now he realizes his colleagues also need someone to talk to and understand the situation. He said he needs to be more cognizant of situations when people are stressed and want to talk about it.

“How do I consult in all that and keep up on it?” he continued. “I think the stress level is probably higher [today].”

Change needed

Kiehne does see some changes occurring to help alleviate stress on veterinarians. For example, he’s hearing more colleagues take time off to coach a child’s team.

“It’s better realizing that there is some life outside of veterinarian medicine,” he said. “I think we need to continue to encourage that — not discourage [it by] saying no, you aren’t working hard enough or you’re not up early enough.”

Unfortunately, when younger veterinarians are struggling, they often won’t seek help from the more-seasoned veterinarians like Kiehne. Instead, he said older veterinarians need to make the first move to be available when someone looks like they need help.

Clients also become stressed, especially during down markets and in the winter when disease is more prevalent. Just offering to listen to the issues can help.

“Letting them understand that yes, they can be frustrated with it and they can be stressed, but they’re also very good at moving forward,” Kiehne added.



Chronic PED cases linger, setting the stage for elimination

The wild run of porcine epidemic diarrhea (PED) striking the pork industry in 2013 has slowed substantially. But chronic versions of PED continue to plague some farms.

“I still get calls about farms that try to get rid of PED and they struggle,” reported Ross Kiehne, DVM, Swine Vet Center, St. Peter, Minnesota. “I’ve been asked to step in and see where [they] are going wrong in those cases.”

Handling chronic PED

Chronic PED problems occur when a farm initially did a good job gathering feedback to expose piglets to the disease. As PED quieted down, less material was available to continue the program, and the farm stopped the practice. This allowed the disease to survive, according to Kiehne.

One solution is to focus on meticulous cleaning of farrowing rooms, allowing the facilities to be disinfected and completely dried over a period of a few days. This may require an earlier weaning age for one turn of farrowing, Kiehne says, but it may stop chronic PED.

Another option is to go back to a feedback program, which Kiehne has used in some cases.

“I’m utilizing that feedback just to try and make sure we’ve got every animal covered,” he said. “This is something you’ve got to work with your veterinarian on because some [people] think it would reinvigorate the disease.

“But I’ve found that is necessary when you’ve been fighting [PED] for too long and not getting rid of it,” he said.

Vaccines also are available to boost immunity to PED. Kiehne suggests working with a veterinarian to determine the best way to use one in your system.

PED elimination from herd

Chronic PED isn’t as devastating as the acute cases, but it still hits the bottom line. For example, 1 day of scours in a baby pig sets it back 3 to 5 days, which is why Kiehne wants PED eliminated from herds.

“There are some farms that will continue to infect gilts because they know they’re in an environment [where] they might not be able to totally get rid of it,” he said. “But my goal always is to totally get rid of PED.”

Kiehne starts his PED-elimination efforts with an evaluation of management including gilt entry and pig movement. “If we’re moving a lot of pigs around and we’re not following a strict all-in, all-out [system], that can be part of the PED problem,” he said.

“I think we know way more about PED now than we did in 2013 and 2014,” he continued. “We can keep it out better now than we could then. We’ve been successful in getting rid of it in so many places.”

Kiehne also believes that someday, PED can be eliminated from the industry.

“But it’s going to be hard,” he added. “I think my outlook would be that we continue to move in that direction because we’re a progressive group of farmers who want to do better.”