Whipworms cause inflammation of the cecum and spiral colon, resulting in loose stools or diarrhea between three to seven weeks after ingestion of eggs. Dark stools containing blood can occur. Untreated whipworm infection causes a chronic wasting disease that lasts for several weeks to months. Infected pigs have a loose or diarrheic stool, and “rail out” or become extremely emaciated. Death can occur or pigs can become chronic poor performers. Swine whipworms are not important as a human disease.

Cryptosporidium spp protozoa rarely cause inapparent infection or mild diarrhea in swine. Cryptosporidiosis in humans primarily occurs after ingestion of water or food contaminated with human-type C. parvum. This is discussed in the Texas Agricultural Extension Service fact sheet L-5162, “Human Cryptosporidium and Cryptosporidiosis.”

Giardia spp protozoal infection in swine is rare, but it does cause disease in humans. Contaminated water is the main source of Giardia spp.

Salmonella typhimurium infection is another important cause of diarrheal disease in show pigs. They become infected by exposure to contaminated swine manure on premises, trailers, or scales. Chronic diarrhea persists until effective treatment is administered. Death can occur in untreated animals.

Salmonella choleraesuis infection also is very important in swine. It causes only a transient or short-term diarrhea followed by systemic or blood stream infection. Affected pigs are very sick and can die or become chronic poor performers if not promptly diagnosed and treated. Both S. typhimurium and S. choleraesuis are called host-adapted salmonella because they cause sickness in swine. Fecal contamination from other livestock, wild animals (including rodents, reptiles, and amphibians), pets, and birds also can contain many species of salmonella. There are more than 2,200 known species that can cause infection in swine but not obvious disease (called nonhost-adapted salmonella). Swine that become infected with nonhost-adapted salmonella shed these bacteria in the feces primarily within the first two weeks after exposure. Regardless of the source of salmonella, if humans ingest a host-adapted or nonhost-adapted type from their own contaminated skin, clothing, equipment, or food, sickness can occur.

Ileitis is an important postweaning disease of swine, especially in commercial operations that supply pork (non-show pig operations). This disease causes a range of problems from sudden death to chronic diarrhea that reduces the rate of gain. Lawsonia intracellularis is the causative bacterium. Though it is rarely the cause of diarrheal disease in show swine, veterinarians consider this organism as a potential cause when making a differential diagnosis. L. intracellularis does not cause human disease.

When feces are totally liquid with no solid form, diarrhea is occurring. A pig with diarrhea caused by infectious agents and/or parasites usually has a reduced appetite or is anorexic, but is still drinking. Vomiting can occur at the start or during diarrheal disease. Weight loss accompanies diarrheal disease and is usually obvious because show pigs are weighed frequently to monitor weight gain. It is common for show pigs to be affected with more than one diarrheal disease condition and have dramatic weight loss.

As soon as the pig develops diarrhea, the cause or causes need to be determined. Loose stool or diarrhea caused by diet usually does not result in weight loss. Restricting feed intake, reducing the protein content of a feed by about 4% and/or substituting rolled or crimped oats or oatmeal as 25% to 50% of the ration usually cures dietary induced diarrhea.

Consult a veterinarian to diagnose infectious and/or parasite-caused diarrheal disease because death is often a result of undiagnosed, chronic diarrheal disease in show pigs.

TGE is the least important of the diarrheal diseases because it is self-limiting and almost never causes death loss in older pigs. Electron microscopic examination of feces at a diagnostic laboratory is the most rapid way to diagnose TGE. For other diseases, a veterinarian typically does the following:

If Escherichia coli is isolated during fecal culture for salmonella, it is probably not important as a cause of diarrhea in show pigs weighing above 40 pounds. If sensitivity testing of the E. coli isolate demonstrates that most antibiotics tested in the laboratory will kill it, then the veterinarian has evidence that this E. coli is normal gut flora and not a pathogen.

During microscopic examination for whipworms, Coccidia oocysts (eggs) and/or Balantidium coli protozoan ciliates might be observed. Coccidiosis usually is considered to be a self-limiting and co-occurring infection that needs no treatment to improve. The B. coli are commensals, benefitting from their relationship with another infectious agent. Neither of these two organisms are the primary cause of diarrhea.

If salmonella diarrhea is diagnosed via culture, a veterinarian will choose the antibiotic that is the most effective and has the shortest withdrawal time. Typically, salmonella that cause diarrhea in show pigs are resistant to the majority of antibiotics; this is why laboratory culture and sensitivity testing are so important.

If pigs, treated for possible swine dysentery with lincomycin (Lincomix®*) or tiamulin (Denagard®*) plus electrolytes in the water, pass a firmer stool in several days, this indicates to the veterinarian that swine dysentery is at least one cause of diarrhea. Medicated water treatment is continued for five days after improvement with lincomycin or for a total of five days of therapy with tiamulin. At the end of the water treatment, recovering animals should be continuously fed medicated feed containing lincomycin (40 grams/ton, no withdrawal time) or tiamulin (35 grams/ton, two-day withdrawal time) to prevent swine dysentery from recurring.

Fenbendazole (Safe-Guard®*) given orally for three days is an excellent parasiticide for whipworm adults and most developing larval stages; deworming should be repeated in a month. Dichlorvos (Atgard®* C) is another commonly used dewormer for whipworms. Ivermectin (Ivomec®*) and doramectin (Dectomax®*) are excellent injectable dewormers and also kill lice and mange, but have variable effectiveness against whipworms.

If pigs are shown multiple times during a season, after each return to the farm isolate them in their own pen. Do not expose other swine (such as breeding stock) on the farm to the many disease-causing organisms that these exhibited swine may have encountered. If show pigs are purchased at a sale that is not at the farm of origin or pigs are bought directly from multiple farms, mixed on a trailer, and transported to a location for distribution to buyers, they potentially are exposed to many disease-causing organisms. The greater the exposure, the greater the likelihood of disease problems. Treating pigs with an antibiotic to compensate for poor health management is usually ineffective. Also, highly effective vaccines are not available for many diseases. As a general rule, it is much easier to prevent swine diseases using good management practices than to successfully treat or vaccinate against disease.

Diet-induced diarrheal disease can be prevented by not overfeeding protein and other ingredients such as fat. Gradually switch the pig from one type ration to another. Make sure the pig finds the water source because water intake is important for adequate feed consumption. A lack of water for a couple of days followed by overconsumption of water can be fatal; this condition is called salt toxicity or water deprivation. Pigs that are “held back” or limit fed to prevent excessive weight gain should always have access to plenty of water.

Whipworms can be prevented by routinely deworming healthy pigs with an effective product (Safe-Guard®* or Atgard®* C) at least once during the feeding period and by housing them on clean dirt, sand, or pasture or uncontaminated concrete floors. Routine deworming in show pigs is commonly performed during the first week after purchase at about 8 to 10 weeks of age or 50 pounds, and then about a month later. Another option is to take a fresh stool sample to a veterinarian for fecal flotation and microscopic examination for whipworm eggs. It takes a minimum of 42 days from the time a pig is infected until adults are present and eggs are passed in feces. This means fecal examination for whipworm eggs before six weeks of age is not necessary. Also, whipworm adults are intermittent egg layers so one negative fecal flotation does not completely rule out whipworm infection.

Swine dysentery is preventable by obtaining pigs directly from a farm that is free of swine dysentery and minimizing exposure to other swine or feces-contaminated premises, trailers, and equipment such as scales. Absence of diarrhea containing blood and mucus, excellent growth performance, and no significant death loss in pigs from weaning through market weight are evidence of freedom from swine dysentery in a herd. In reality, the credibility of swine dysentery-free status is based on each breeder’s reputation.

The following medications are included in show swine rations by feed manufacturers to prevent swine dysentery:

An alternative and less expensive strategy is to use the continuous lower levels of Lincomix®* (40 grams/ton) or Denagard®* (35 grams/ton) in feed to minimize sickness if pigs are infected.

Mecadox is another alternative feed medication to prevent swine dysentery, but it has an extremely long withdrawal time.

It is best to take show pigs off of all medication (even 0-withdrawal medication) at least 24 hours before exhibition.

The best prevention for salmonellosis is to obtain the healthiest pigs possible and to manage pigs to reduce stress and maintain good sanitation practices. It is not a good practice to put antibiotics in the feed to prevent salmonellosis because antibiotic resistance is very common with salmonella species (however, Mecadox®*—50 grams/ton fed continuously, 42-day withdrawal before slaughter—is approved for the control of salmonellosis caused by S. choleraesuis). Vaccines are available for S. typhimurium and S. choleraesuis, but these have not been widely used in show swine. There are numerous sources of salmonella, and host-adapted and nonhost-adapted salmonella can cause human disease if the organisms are ingested. Animal and human salmonellosis can be prevented by proper sanitary measures such as hand-washing, proper livestock and pen management, bedding changes, premise cleaning and disinfection, pasture rotation, rodent control, and proper food preparation and cooking.

TGE can be prevented by not exposing swine to sources of the virus. Vaccines are available that control the effects of disease; they do not prevent infection with TGE.

A veterinarian should be consulted to assist in the diagnosis, treatment, and prevention of this and other conditions.

 Refer to Texas Agricultural Extension Service fact sheet L-5203, “Swine Pneumonia,” for information on swine respiratory disease. The Pork Industry Handbook fact sheet PIH 36, “Swine Arthritis,” contains information about lameness in swine. The Pork Industry Handbook is available from Purdue University Cooperative Extension Service, 765-494-6794 (phone).

 For more information:

Selected articles in Proceedings of the American Association of Swine Practitioners. 1995-1999.

Selected articles in Proceedings of Allen D. Leman Swine Conference, 1997 and 1998.

Stewart, B.S., Stromberg, B.E. and Lawhorn, D.B., “Internal Parasites of Swine,” PIH - 44, Pork Industry Handbook, Purdue University, West Lafeyette, Indiana, 1993.

Harris, D.L., Glock, R.D., Joens, L., et al, “Swine Dysentery,” PIH - 56, Pork Industry Handbook, Purdue University, West Lafeyette, Indiana, 1993.

Becker, H. N., Meyerholz, G.W. and Gaskin, G.W., “Selection and Use of Disinfectants in Disease Prevention,” PIH - 80, Pork Industry Handbook, Purdue University, West Lafayette, Indiana, 1990.

Sulaiman, I.M., Xiao, L., Yang, C., et al, “Differentiating Human from Animal: Isolates of Cryptosporidium parvum,” Emerging Infectious Diseases, Vol. 4, No. 4, 1998.

Feed Additive Compendium, The Miller Publishing Company, Minnetonka, Minnesota, 1998.

Veterinary Pharmaceuticals and Biologicals, 9th Edition, Veterinary Medicine Publishing Company, Lenexa, Kansas, 1995/1996.

 The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas Agricultural Extension Service is implied.

 The USER is always responsible for the effects of products administered. Always read and follow carefully the instructions on the product label.