The clinical incidence of the bacterial disease erysipelas has grown more prevalent in the last few years.
In general, vaccines have done a good job of controlling clinical signs due to the organism Erysipelas rhusiopathiae.
Case Study No. 1
This northwest Iowa farm received 3-week-old weanling pigs from two sources — one sow unit in Canada, the other in Minnesota. The pigs were brought into 500-head nursery rooms where they stayed for approximately eight weeks. From the nursery, pigs were moved into outside finishing.
The producer had about 3,000 finishing spaces — 800 in a modified-open-front building and 2,200 in converted farm buildings. Mortality in this operation averaged 1.6% in the nursery and 3% in finishing.
In July 2002, within a 24-hour period, this producer had 15 dead pigs in three pens in the modified-open-front finishing building. The pigs weighed over 230 lb. and had no external lesions. No signs of illness were noted in any of the finishing pigs on the previous day. This group of pigs had been vaccinated one time at 40 lb. with a commercial erysipelas vaccine.
Postmortem examinations were performed on several of the dead pigs. No obvious lesions were observed, however, pigs had enlarged livers and spleens.
As we walked through the groups, we found pigs that were reluctant to get up and move away. About 20% of the pigs appeared lethargic. A few pigs had raised, red skin lesions on the rumps, sides and across their backs. Many pigs had a fever of over 107∞ F. Tissues were obtained for a culture and sensitivity.
Based on postmortem and clinical signs, the entire group was injected with procaine penicillin G at 12,000 IU/lb. The entire group was also given a commercial erysipelas vaccine.
In 24 hours, the group showed much improvement. The lethargic pigs were limited to the pigs that were sickest the previous day. The individuals that were the poorest the previous day were injected with procaine penicillin G at the same level for two more treatments.
The same three pens in the modified-open-front building also had mortality problems due to erysipelas when the next group reached market weight.
Case Study No. 2
In July 2002, we were called to a 2,000-head finishing site with a history of sudden death in 240-lb. finishers. This site included two barns with one, 1,000-head room per barn. These were totally slotted, double-curtain-sided buildings. Forty pigs had been lost in two days, primarily from one end of one of the finishing buildings.
Upon examination, many lethargic pigs were noted. Many pigs had raised, diamond-shaped red lesions on the skin of the hams and back. Temperatures of pigs were commonly above 106∞ F. Postmortem examinations revealed only enlarged livers and spleens. Tissues were removed for culture and sensitivity testing. Erysipelas was isolated from all submitted tissues.
Since vaccine has a 21-day withdrawal, the entire group was injected with 12,000 IU/lb. of procaine penicillin G. In 24 hours, the pigs showed great improvement. Pigs with the most clinical signs were injected for two more days.
These pigs had received an injectable dose of commercial erysipelas vaccine at approximately 30 lb. A booster of a commercial oral erysipelas vaccine was administered at 70 lb.
Diagnosis and Treatment
Identification through culture and sensitivity testing is a reliable way to diagnose erysipelas.
Vaccination still provides the best disease control that we can give pigs infected with erysipelas.
Oral and injectable vaccines are available. Care is needed in handling and administering these vaccines. For pigs, two doses after 8 weeks of age are necessary for good immunity. Three doses may be needed if the challenge is great in some facilities.
At times, vaccine failure has been blamed, only to discover that they were stored or administered incorrectly. This is especially true of an oral vaccine that requires special attention to maintain viability until it reaches the pig's nose at the drinker.
There are also times when the amount of antigen that challenges the pig overwhelms the immunity that the pig has received through vaccination.
Treatment of pigs with procaine penicillin G has been sufficient for most cases we see. Care needs to be taken if an extra-label dose of penicillin is given. Dosages larger than the 1cc./100 lb. of body weight require an extended withdrawal time. Contact your veterinarian for the appropriate dosage and withdrawal times for the size of pig you are treating.