When 1+1 is more than 2: interactions causing the Porcine respiratory disease complex (PRDC) (3/3)

8. How should the control of PRDC be approached in the field?

If there was one thing Cano and Segalés made clear, it’s this: there’s no single solution to PRDC. You can’t throw antibiotics at it, or count on vaccination alone, or hope it just fades out over time.

Cano framed it this way: “PRDC control isn’t a protocol, it’s a system.” That system has to start with understanding what you’re dealing with and then building a response that fits the specific dynamics of your herd.

Here’s how they broke it down:

• Accurate diagnosis as the starting point: Without it, you're guessing. Segalés emphasized that you need to know which pathogens are involved, what lesions are present, and how transmission is occurring in your specific setup. This means combining necropsy, lab results, and production data, not relying on just one.
• Identify the predominant pathogens: You don’t have to eliminate everything, but you do need to know what’s driving the clinical picture. If Mycoplasma is just a background issue but PRRS is flaring, your strategy should prioritize stability and control of PRRS.
• Adjust vaccination programs based on flow and risk: This isn’t about checking boxes, it’s about tailoring timing and product selection to how your system operates. Cano gave the example of flow-based adjustments where certain nursery phases were moved to earlier vaccine timing due to viral circulation patterns.
• Improve management and biosecurity: Ventilation, pig flow, stocking density, cleaning protocols, all of these either amplify or suppress PRDC. Segalés reminded us: “Biosecurity isn’t a poster on the wall. It’s behavior, every day.”

Click here to watch the recorded webinar.

9. How do different production flow systems influence PRDC?

If there’s one structural decision that determines whether PRDC is manageable or chronic, it’s how pigs move through the system. For both Cano and Segalés, this topic was non-negotiable: flow design either sets you up for success or traps you in an endless disease cycle.

• Continuous flow = continuous problem: In continuous flow systems, new pigs are constantly being introduced into partially cleaned environments — often into barns where older pigs, lingering pathogens, and leftover immunity gaps already exist. According to Cano, this setup creates “the perfect setting for PRDC to recycle and intensify.” Pathogens don't just survive — they evolve and recirculate, infecting every new batch with a slightly different twist.

Segalés added that in these systems, diagnostic patterns often show multiple pathogens co-circulating for long periods, making it harder to time interventions or interpret vaccine responses. “If your pigs never stop moving, your problems never get a break,” he said.

• Batch production (all-in/all-out) = a chance to reset: In contrast, all-in/all-out (AIAO) systems — when implemented properly — give farms the ability to break the infection cycle. Pigs enter together, exit together, and the facility is fully cleaned and disinfected between groups. This allows:
  • Better pathogen control
  • Cleaner implementation of vaccine programs
  • Clearer interpretation of clinical or subclinical issues
  • Easier flow-specific diagnostics

Cano emphasized that even partial AI/AO (e.g., at the room level in nurseries or finishers) can have significant benefits if supported with proper sanitation and downtime.

Your production flow is not just logistics; it’s part of your disease control strategy. As Segalés put it: “If you want control, you need pauses. PRDC thrives where systems never stop.”

Click here to watch the recorded webinar.

10. How can we make sure that control strategies are implemented on the farm?

Even the best PRDC control plan means nothing if it stays on paper. As Cano put it: “Execution is everything. A plan is just a plan until someone checks if it’s actually happening.”

Both speakers agreed: implementation is often the weakest link. It's not about knowing what to do, it's about making sure it actually gets done, correctly, and consistently.

Here’s how they suggest closing the gap between planning and doing:

• Communicate clearly, what, why, and how: Don’t just say “we’re vaccinating today.” Explain what’s being done, why it matters, and what each person’s role is. When staff understand the reason behind the task, they’re more likely to follow through with care.
• Assign ownership: Every intervention, from vaccination to lung scoring to cleaning, should have a clear person responsible. Segalés emphasized that “shared responsibility is often no responsibility.” Someone needs to be accountable for each step.
• Create feedback loops: Field observations matter. If caretakers see coughing or poor response to treatment, that information needs to flow back to the vet team quickly, not wait until the next visit. Cano encouraged teams to build a culture of reporting, not just reacting.
• Audit regularly, not as punishment, but as learning: Follow-ups shouldn’t be about catching mistakes, they should be about refining the system. Segalés suggested simple audit checklists for things like vaccination timing, record-keeping, and biosecurity compliance.

Implementation is where theory meets practice. And as Cano said, “The best protocol in the world won’t work if no one’s watching the barn.”