For years, the swine industry has talked at length about multiple pathogens and multiple infectious agents. JD Fiechtner, senior key account veterinarian for Boehringer Ingelheim, says only recently has the industry begun to fully realize the impacts of two infections affecting the pig at the same time.
“For a long time, we thought of them separately, as just a one plus one – an additive component,” Fiechtner explains. “What the industry is realizing now is that we are seeing worse outcomes from these infections when they’re together than when we just considered them independent of each other.”
Two recent studies back up the compounding impact pigs face when hit with more than one pathogen at a time. Scientists looked at the impact of co-infections of porcine reproductive and respiratory syndrome (PRRS) plus Lawsonia intracellularis and PRRS plus porcine circovirus type 2d (PCV2d).
“Most everybody is dealing with PRRS infections, and there is not any one answer to manage that disease,” Fiechtner says. “It’s very common, and it’s very common to be frustrated with it.”
A Dynamic Discovery
In the first study, scientists evaluated the highly virulent PRRS 1-7-4 strain in combination with PCV2d. The study revealed that giving a PCV2d vaccine as prevention or protection results in better economic outcomes in co-infected PRRS pigs. Not only did they see a decrease in mortality, but they also saw a decrease in the number of pigs treated for health challenge signs that would require an antibiotic or other supportive therapy.
“We call this dynamic pig health, because it is a dynamic system within the pig,” he says. “It’s not just one issue. You have to consider all the aspects of disease. That’s why looking at the overall pig and the overall challenges when making your intervention strategies is very important.”
The second study evaluated PRRS with Lawsonia intracellularis. Typically, studies don’t connect the respiratory component of the PRRS virus with a gut infection like Lawsonia.
“We usually don’t think about a common tie between those two organ systems – enteric and respiratory,” Fiechtner says. “But in this study, we proved that even with subclinical (or less than obvious infection of Lawsonia), there was increased mortality and decreased average daily gain — worse than what was expected.”
Fiechtner believes most people who work in the pork industry have a gut feeling about the deeper impact of co-infections.
“These studies put some facts to what many who work in swine health assumed and helped us predict some economic costs and/or benefits of tailoring your approach to mitigate co-infection concerns,” he says.
Strategize Solutions
Working with a herd veterinarian is key, Fiechtner says. Find a veterinarian who is informed on pathogens present in the industry and is connected to the diagnostic labs.
“Diagnostic labs have made great improvements in the last decade on testing and specifics of disease pathogens,” he points out. “This allows you to tailor vaccination strategies or treatments to obtain the best outcomes economically from these pigs.”
For example, with PCV2d, Fiechtner says there have been good vaccines available for a number of years. The challenge is that the predominant genotype has shifted from PCV2a to PCV2d. Most systems will still say they have good coverage with their vaccines, but some are seeing impacts that they don’t like, that are negatively impacting herds. This knowledge allows them to tailor a specific vaccine to approach a “d” problem to obtain a better outcome.
One of the challenges with PRRS plus Lawsonia is that subclinical Lawsonia is hard to “see” in barns, he explains.
“Lawsonia is a silent thief,” Fiechtner says. “In economic studies from Iowa State, it costs anywhere between $3 and $10 a pig with subclinical Lawsonia, and up to $17 a pig with a clinical infection. There are some big dollars that can be lost here.”
That’s why it’s important to understand your herd’s health in order to strategize prevention. Although there is not one perfect method, he cautions against underestimating biosecurity.
“If you can prevent entry of any disease to your herd, that would be the best mechanism,” he says. “But a lot of these pathogens I’m talking about are endemic, which means they’re already present so you can’t exclude them. But you can minimize their impacts.”
To stay in business to provide healthy, nutritious protein to the global population, producers must be able to do so in a reasonable, economic and sustainable manner.
“Nothing trumps health when you want the best outcomes for your pig production systems,” Fiechtner says. “Prevention is the key. Work with your herd veterinarian who is familiar with your system and health challenges to tailor your interventions and preventions to obtain the best outcomes possible.”
Bottom line? Have a plan on how to deal with disease, minimize impacts, mitigate problems and obtain support from trusted advisers.
