Digestive disorders are common in growing and finishing pigs. One or a combination of causes can trigger these disorders. Infectious causes and the ability to limit exposure to them can be very important.
In many diseases, environmental exposure affects the infective dose of an organism. Small doses may show no clinical signs while large exposure may lead to severe clinical disease.
Ileitis, caused by Lawsonia intracellularis bacteria, is the major infectious cause of diarrhea in growing pigs. Ileitis has both a chronic form and an acute form, and diarrhea is the primary clinical sign. Feces consistency in the chronic form ranges from watery to soft and often looks like undigested feed. The acute form can contain blood.
Ileitis can cause decreased weight gain as well as death loss. Fiber in the diet appears to decrease clinical disease.
We still see some hemolytic E. coli infections, most occurring from 40 to 80 lb. With culture and sensitivity work, we can get a pure culture of hemolytic E. coli from the ileum.
Gastric ulcers in growing pigs are common in all facility types. With gastric ulcers, the inner lining of the stomach erodes.
Although infectious organisms have been isolated from pig stomachs, there is no proof that they cause ulcers in pigs. Some data suggest that genetics might play a role.
Fineness of feed grind has been implicated. As diets are further processed, the rate of stomach ulceration increases. We see ulcer rates go up considerably in some cases with pelleting of like diets.
In many cases, we see a spike in ulcer-related deaths following an off-feed situation, such as that caused by a respiratory outbreak.
In managing any mortality, it is helpful to record when the losses occur. Often a pattern of losses can be identified when we look at days on feed. This can help determine the initial cause of the ulcer storm.
A relatively new concern is a condition caused by the Brachyspira pilosicoli organism that infects the large intestine. Most clinical signs are noticed after pigs leave the nursery. Diarrhea is the most common sign. The feces resemble undigested feed or a soft stool. B. pilosicoli can be confused with ileitis because of similar feces and history.
Common treatments of B. pilosicoli include antibiotics used on other organisms in the spirochete family (i.e., carbadox, lincomycin, tiamulin and gentamycin). All-in, all-out (AIAO) production practices and between- group sanitation will decrease the exposure to this organism. This organism has become more prevalent in the last few years, especially in modern confinement facilities.
Case Study No. 1 We were called to a single site, 200-sow, farrow-to-finish operation with a history of sudden death in the finisher. Postmortems were performed on two, 180-lb. finishing pigs. Both had very pale skin. Each pig had signs of thickening of the ileum (the last part of the small intestine). The inside of the intestine was filled with clotted blood.
Histopathology at a laboratory confirmed acute ileitis. Since this was an ongoing problem, we instituted a feed purge medication program, which uses a prevention level of Tylan for one week of three during the finishing phase.
Case Study No. 2 We were called to a wean-to-finish unit receiving 800 weaner pigs every four weeks from a single-source farrowing unit. The pigs are placed in an AIAO by site nursery for eight weeks.
Pigs are then moved to a two-building finisher site where pigs are AIAO by building. The site had an ongoing problem with late finisher respiratory disease. After plotting closeout mortality, we found an increase in mortality during the respiratory outbreak, and again, 14 to 21 days after respiratory symptoms occurred. The second spike was due to the secondary gastric ulcer mortality.
After a laboratory work-up, a control program started for Mycoplasmal pneumonia and swine influenza virus. Subsequent groups have had decreased death loss due to respiratory disease and gastric ulcers.
Case Study No. 3 We were called to a conventional, 60-sow, farrow-to-finish unit complaining of diarrhea in 40-lb. pigs. Previous groups had shown similar clinical signs. Pigs examined were in a barn with an outdoor feeding floor. Approximately 30% showed signs of diarrhea. Death loss was low, but the weight spread in the group was wider than expected. They were treated with a feed- and water-grade antibiotic without success. The group responded to another feed-grade antibiotic within five days. Prevention in subsequent groups has been maintained.
It is important to get an accurate diagnosis when dealing with digestive disorders in pigs. Your veterinarian can help lay out a control program.