Disease Reduction and Elimination Strategy for Covid-19 Situation

June 3, 2020 — 

Pork producers are being forced to euthanize large, healthy, market-ready hogs because it is not possible to get them harvested/processed due to the significant and on-going reduction in packing plant capacity. Going forward, the packing plants are predicting no more than 90% of their previous capacity as they implement CDC guidelines for worker safety. This has resulted in some producers being forced to make the difficult decision of euthanizing animals due to welfare issues and/or to make room in the production chain for the next pigs. The National Pork Producers Council estimates that millions of pigs will be euthanized to get us through this present and near-future reduction in packing plant capacity. How can we turn this negative into a positive?

If forced to make the decision to remove swine herds, AASV is encouraging farmers to work with their veterinarians to strategically remove populations or herds that have long-term but active health problems originating from endemic diseases, whenever possible. Despite that government funding is still uncertain, we need to act now to remove animals that are facing welfare or market issues.

The industry goal of a targeted effort is to help improve the overall herd health of the entire swine industry. Minimizing disease challenges enhances animal wellbeing. Endemic diseases pose a significant loss in performance and increased vaccination and medication cost to farmers.

A targeted disease reduction program might help to ensure the humane removal of animals from the market in a controlled manner. It might also improve the health of both the individual and national herd that would support the One Health Initiative that could result in decreasing antibiotic usage in livestock. At the same time, it could improve the long-term food security by improving our global competitiveness, keeping U.S. producers in business supplying the food chain.

This type of effort could target some of the market-ready pigs and younger pigs that are coming up through the production chain. In addition, it could reduce the infection pressure by reducing the number of animals with chronic health problems while providing an oversupply relief valve for the industry. If enough producers agree to participate, it may start regional elimination programs that could even ultimately result in eradication of some of these diseases.

This may include site and herd depopulation plans especially if multiple agents are involved. Other options would be to implement disease control procedures such as herd closures, partial depopulation, conversion to batch farrowing, etc. to stabilize the herd and reduce the shedding of viruses and bacteria. Knowing that every production site is unique with its own constraints, producers and herd veterinarians would work together to develop these herd plans to address each farm's individual concerns. For instance, some wean to finish sites may be infected without any concerns at the sow farm source, so clean-up could be easily achieved.

Targeted interventions, such as those described here, allow farmers and veterinarians to focus efforts on lower health status herds. Targeting these herds could be a silver lining, turning a terrible situation into a much better outcome achieving the long-term goal of improving individual and national herd health.

Indications of Active Infections

Pathogen	Breeding Herd	Growing Pig Herd
PRRSv	A herd exhibiting off-feed sows, death loss, abortions, stillbirths, increased PWM and/or returns with PCR positive test results.	Group of pigs exhibiting acute respiratory clinical signs accompanied with sudden increased in mortality together with PCR positive results oral fluids and/or serology.
Coronaviruses	Breeding herd with sudden increase in sow and piglet scouring throughout the farrowing barn, increased PWM and/or PCR positive results.	Growing pigs undergoing an acute episode of watery diarrhea with positive PCR results to coronavirus either fecal sample and/or oral fluids.
Brachyspira hyodysenteriae	Acute onset of diarrhea containing blood-mucous in growing pigs. Pathogen confirmation through PCR and/or culture.	Acute onset of diarrhea containing blood-mucous in growing pigs. Pathogen confirmation through PCR, culture and/or histopathologic lesions.
APP	Clinical outbreak acute mortality with characteristic lung lesions and purple abdomen and bloody nasal discharge, with PCR+ and/or isolation of pathogen.	Acute increase in mortality rate (with or without bloody nasal discharge), purple abdomen and characteristic lung lesions with PCR+ and/or isolation of APP.
Mycoplasma hyopneumoniae	Persistent dry nonproductive cough. Increased number of gastric ulcers as outbreak persists PCR + on laryngeal or bronchial swabs and/or characteristic histopathology lesions present in lung tissue. Serologic positives if nonvaccinated	Persistent dry nonproductive cough. Typically occurring in mid to end of finishing phase. PCR + on laryngeal or bronchial swabs and/or characteristic histopathology lesions present in lung tissue. Serologic positives if nonvaccinated

This document was proposed and reviewed by the following AASV members: Matt Ackerman, Emily Byers, Joe Connor, Cesar Corzo, Steve Henry, Tim Loula, Jay Miller, David Pyburn, Rebecca Robbins, Paul Sundberg, Pete Thomas, Liz Wagstrom, and Paul Yeske. Publication in the AASV e-Letter was approved by the AASV Board of Directors.