Ileitis is a disease mainly in growing pigs that has a large economic impact. Financial losses can come from lowered performance, such as poor feed conversion or slow average daily gain, as well as increased number of culls and mortality. Because gilt development involves growing out swine, ileitis can cause significant losses in gilt developer units and the early gestation period in Parity 1.
Ileitis is caused by bacteria that live within the cells of the intestinal lining. This organism can be passed from sow to piglet and pig to pig or picked up from the environment that the pig lives in. Pigs become immune to the bacteria, but controlling the exposure that leads to immunity or actively immunizing the pig is the key to control.
There are two common control programs for ileitis. The first program is the use of a commercial vaccine called Enterisol (Boehringer Ingelheim Vetmedica, Inc.). This is an oral vaccine that can be administered through a proportioner. It is a live vaccine, so care needs to be taken to make sure that it is still living when it reaches the pig’s gut. The protocol used with this vaccine includes clean water lines, chlorine-neutralizing additive to water and no use of feed-grade antibiotics a few days before and after vaccine administration.
The second control program is feed-grade antibiotics to limit the economic impact of disease while allowing natural exposure to create immunity.
These programs use purge treatment of susceptible pigs with either intermittent feed-grade or water-therapeutic antibiotics. The timing of purge medications is specific to the farm. Some farms use this approach once per month, and others may not use any purge until near marketing. Common feed-grade antibiotics used for ileitis control include carbadox, tiamulin and tylosin. Water medications used are tiamulin and tylosin.
Ileitis features both chronic and acute forms. The chronic form is also known as “garden hose” gut due to the gross appearance of the last part of the small intestine called the ileum. The chronic form is characterized by diarrhea in the growing through finishing stages of production. The diarrhea can vary from the color of feed to chocolate pudding to hemorrhagic. These pigs lose condition and their backbones may begin to be visible. This form will generally start with a few pigs in a group, and if left untreated, will snowball to up to 30-40% of the group.
The acute form is characterized by sudden death in pigs. Often the mortality is seen in heavyweight finishing pigs. As you walk pens, you can see black, tarry feces from pigs that are affected. These pigs are very pale because they are bleeding out into the ileum. Mortality in finishing pigs and during gilt development can occur in multiple numbers in 24 hours. Losses will continue if left untreated.
Case Study No. 1
We were called to a farrow-to-finish site with a history of diarrhea in finishing pigs. This was a farm that batch farrows 30 sows every five weeks. The growing pigs were examined and a brown diarrhea was noted in pigs 65 days postweaning. A postmortem examination done on one pig showed the last part of the small intestine was thickened and the intestinal contents contained some fibrin and blood mixed with the feces. This group was started on tiamulin in the water at label directions followed by tylosin in the feed at 100 g./ton. The next and subsequent groups to move into the finisher were vaccinated 2½ weeks after entering the nursery.
With the oral vaccine, we need to get pigs vaccinated 35-45 days prior to the onset of seeing clinical signs. This flow of pigs has responded nicely to vaccination, and subsequent groups have remained free of visible ileitis.
Case Study No. 2
We were called to a 4,800-head, wean-to-finish site that consisted of two, 2,400-head, double-wide, tunnel-ventilated barns. These pigs had been on feed 155 days. The caretaker found five dead market weight pigs one day and six dead pigs the next day. A walk-through of the barn showed numerous areas of black feces on the slats and a number of pigs that were quite pale. Postmortem examination of one of the pigs revealed a thickened small intestine with hemorrhagic intestinal contents. This group was placed on tylosin in the water at the label concentration for five days. Mortality stopped and the group was marketed after adherence to withdrawal times.
A rapid diagnosis and action plan for control of ileitis is essential to stopping economic losses. Since this can occur in late finishing, be sure to observe all labeled withdrawal times for antibiotics.