Posted by Dr. Steve Dudley on June 16 2005 10:37
Swine Newsletter 2nd Quarter 2005
Many producers in Southwest Minnesota and across the United States have implemented Enterisol Ileitis Oral Vaccine. This is a modified live vaccine that helps to prevent clinical outbreaks of ileitis along with improving feed conversion and average daily gain.
Ileitis is caused by a bacteria known as Lawsonia intracellularis. This is a bacteria that is transmitted by ingestion of infected manure or fecal material. Pigs typically are exposed at 60-100 pounds and most clinical outbreaks occur from 80-150 pounds. Signs of ileitis may include:
- Diarrhea with undigested feed particles
- Blood in the manure
- Sudden death loss
Chronic forms of ileitis can be seen with fall behind pigs that look gaunt and may have their backbones showing. There have been two control programs typically utilized for the control of Ileitis. One involves using feed antibiotics with rotations of Tylan, Lincomix, or Denagard. The second control method has been to use ileitis vaccine by Boehringer.
Recently there has been an increased incidence of disease breaks on vaccinated pigs. We want to review important parameters when utilizing this vaccine. On farm investigations have indicated that improper timing of the vaccine accounts for 45% of the breaks. Improper timing is indicated if the outbreak of ileitis occurs within 6-8 weeks after vaccination. Another 15% of the cases associated with outbreaks were misdiagnosis or other causes of diarrhea. Lastly, 40% of the cases were incomplete immunization or the pigs did not seem to respond adequately and avoid clinical disease.
According to Boehringer Ingelheim, the common practice of using a half dose of vaccine has not been helpful in preventing disease. Their challenge studies indicated that by using the full dose they were able to improve average daily gain and performance parameters and when only using half or quarter doses they were not able to see average daily gain improvements.
It’s important when using ileitis vaccine to optimize the vaccination timing. The vaccine needs to be in the pigs 3-4 weeks prior to the infection. An outbreak doesn’t occur for 3-4 weeks after infection so vaccine timing needs to be placed 8 weeks prior to a clinical outbreak or serological conversion. There is a blood test that we can use to detect the presence of ileitis. This along with fecal swabs are very good tools to determine when infection occurs.