While porcine reproductive and respiratory syndrome (PRRS) grabs the majority of the headlines when it comes to swine diseases, Streptococcus suis and Haemophilus parasuis (HPS) have quietly (or not so quietly) stood the test of time.
The hog industry has tried management changes such as segregated early weaning (SEW), all-in all-out pig flow and multiple-site production to control and eliminate challenges such as strep and HPS.
However, our practice continues to deal with these bacteria almost daily, as we search for treatment methods to handle these disease challenges.
Case Study No. 1
We were called out to a 4,800-head contract finishing facility. The unit was comprised of four, 1,200-head, totally slotted, tunnel-ventilated buildings. Pigs were loaded into the facility over a two-week period, and had been on the site for 4-6 weeks.
The producer called on a Monday morning complaining that approximately 20 pigs had died in one barn over the weekend. The contract finisher reported some pigs exhibited labored breathing, but thought that the losses were primarily of a sudden-death nature. The system had no history of Actinobacillus pleuropnemonia, which can cause sudden death in pigs within a few hours to a few days.
When we arrived at the farm, we found multiple pigs thumping and lethargic and several more dead pigs.
Necropsy revealed an extreme amount of fibrinous pericarditis, or fibrin (a white, insoluble, fibrous protein) surrounding the heart. There were also large amounts of fluid and fiber in the abdominal cavity. Based on our necropsy, we suspected HPS to be the culprit. Tissues were hand-delivered to the University of Missouri diagnostic laboratory. A positive diagnosis of HPS was made within 24 hours.
Due to the severity of the case, we mass-injected the entire barn with ceftiofur hydrochloride and ran high levels of tetracycline in the water.
Oddly, only one barn out of three was affected. The company's fieldman believed that a thermostat/ventilation malfunction during the weekend stressed the pigs, allowing HPS to express itself. We were not able to confirm that observation.
Case Study No. 2
A 300-sow, farrow-to-finish facility was working through PRRS challenges. The sows had been mass vaccinated and the piglets likewise vaccinated for PRRS. Strep and HPS were also present.
In this case, healthy newborn pigs exhibited swollen navels and joints by 7-10 days of age. They were being weaned at 21 days and would fall out in the nursery, most 7-14 days postweaning. Fallout pigs continued through 10-12 weeks of age.
A consistent finding was strep in the joints of very young pigs and a combination of strep and HPS in the nursery through grower age pigs. Typically, pigs would appear to stop eating, become gaunt, long-haired and rough, and eventually be euthanized. Once pigs showed clinical signs, treatments were not effective.
Necropsies of nursery/grower pigs almost always revealed severe adhesions of the heart, lungs and chest cavity.
Antibiotic and vaccination programs were implemented simultaneously during the PRRS stabilization process. An autogenous strep/HPS vaccine was developed. This product was given to sows at five and two weeks before farrowing. Piglets were vaccinated at 7 and 21 days of age.
The antibiotic ceftiofur sodium was also given at birth and 7 and 21 days of age. Feed medications included tilmicosin followed by tiamulin/chlortetracycline. Pulse dosing of prescription water medications were also given to pigs at 5-10 days postweaning.
Hospital pens were provided for fallouts, and Solutein (APC, Inc.) was administered via drinking water.
These protocols were costly in terms of inputs and labor. In this case, the owner was willing to implement these protocols due to the severity of clinical signs taking place.
Our goal, as the herd stabilizes to PRRS virus, is to reduce the amount of intervention needed.
At this point, water medications have been dropped in the nursery, and less feed medications are being required. We have continued with the three-dose regimen of ceftiofur sodium through the summer months.
Strep and HPS continue to be common challenges on many hog farms. A combination of strategies and intervention can help reduce these challenges.
There is ongoing research in the veterinary community to stimulate immunity for strep and HPS within younger pigs via live bacteria.
Monitoring pig death loss with necropsies, accurate diagnosis and proper antibiotic sensitivity testing are all essential components in helping manage these problems correctly.