Protecting the health of the nation's swine herd is a continual challenge. Just when we think we are making progress on cleaning up a disease, such as pseudorabies, there is another disease waiting around the corner to take its place.

Over the last 15 years, we have seen porcine reproductive and respiratory syndrome (PRRS) virus emerge as one of the most challenging problems we face today. The different strains of influenza and how they change continue to challenge our control strategies for this disease.

In the past couple of years, Clostridium Type A and Clostridium difficile have become diseases affecting more and more operations.

And if that's not enough, some of the old diseases like Streptococcus suis and Haemophilus parasuis still plague some pigs.

Case Study No. 1

A 50-sow, farrow-to-finish operation previously had baby pig diarrhea caused by Clostridium perfringens Type A. This scour affected pigs from 1-3 days of age in about 40% of the litters. The farm had used a pre-farrow vaccination containing E. coli and Clostridium perfringens Type C. Our recommendation was to add an autogenous Clostridium perfringens Type A vaccine to the pre-farrow immunization program and 250 g. of BMD/ton of lactation diet.

The farm had responded quite well until recently, when 20% of the litters broke with a scour, again at 1-3 days of age. Samples were submitted to the diagnostic laboratory and Clostridium difficile was isolated. The only control option available was an autogenous Clostridium difficile vaccine.

We also reviewed with the producer the importance of the sows having good appetites, milking well, and reducing any external stresses that cause the pigs to scour. We reviewed farrowing house temperatures and increasing air movement through the summer to keep sows cool. So far, efforts to reduce stress and use of the autogenous vaccine look promising.

Case Study No. 2

A 1,300-sow, farrow-to-finish operation has a 3,000-head, off-site nursery. This nursery consists of seven rooms with 500 pigs per room. Each room is managed all-in, all-out; however, the building is continuous flow.

During the last 12 months, this nursery has experienced considerable death loss due to PRRS virus and postweaning E. coli.

Through some vaccination and management changes in the sow herd, we were able to reduce the amount of nursery losses attributed to PRRS. Nutritional changes and vaccination of these pigs helped reduce postweaning E. coli.

After this improvement, there was a sudden increase in death loss with no apparent change in overall health. Healthy-looking pigs, 21-28 days of age, were dying following weaning. Laboratory work isolated a Strep suis Type 7 organism from the brains of several pigs.

To control the strep, we advised injecting all the pigs at weaning with penicillin and keeping room humidity levels below 65%. Nursery death loss has dropped from 4% down to 2%.

Case Study No. 3

This case is more of a case of mistaken identity. A producer reported some death loss in nursery pigs that came from a sow farm we do veterinary work for. A local veterinarian performed a postmortem examination on nursery pigs, diagnosing the problem as “Haemophilus.” The message we received was that these pigs were infected with Haemophilus parasuis, so we vaccinated the sows for this disease.

But the problem persisted. As we investigated further, it became evident that the veterinarian's diagnosis was for Haemophilus “pleuropneumonia,” from which the name was changed to Actinobacillus pleuropneumonia more than 10 years ago.

This is an example of not only an old disease still causing problems, but also an example of an old disease now referred to by a different name. Better communication between all parties would have avoided this confusion and benefited everyone.


Whether it is an old disease, a new disease or a reemergence of an old disease, accurate diagnosis is always essential. Prevention and control protocols change as time goes on, and the industry as a whole has a feeling for what works and what doesn't.

When three-site production first became popular, some thought it wouldn't be long before swine diseases would no longer be a significant problem for the pork industry.

Nearly 10 years later, it appears safe to say that pig disease is still a significant player when it comes to producing pigs profitably.

As always, work with your local veterinarian to get an accurate disease profile of your herd at all stages of production, to ensure that the decisions made are economical, appropriate and effective.