Preventing and treating diarrhea in nursery pigs
Diarrhea in newly weaned pigs has always been a challenge for the swine industry. When combined with a move to a new facility, the stress of weaning can often trigger an enteric challenge in the nursery. If this is a challenge on your farm, consider focusing on these three areas: sanitation, pathogen control and proper nutrition.
Freshly weaned pigs have just experienced an incredibly stressful change, and that stress can be highly detrimental for their already immature immune systems. On top of this, any maternal antibodies that were conveyed to the pig from the sow will be waning within the first two weeks of placement, thereby elevating their risk from any exposure to environmental pathogens. Effective power-washing must be completed between every group entering the facility — especially if previous groups have faced a challenge. De-greasers and/or hot water will be a great help at eliminating any biofilm on floor and feeder surfaces, which cold water alone may not be able to remove. A post-washing inspection is also helpful, as spaces in the floor, under the lip of the feeder or underneath water bowls are commonly missed — and these areas can all harbor enough pathogens to make a weaned pig sick.
Once the pens have been sufficiently cleaned, it is important to also select a disinfectant that will effectively eliminate the pathogens present in the facility. There are several product options on the market, all of which have their pros and cons. Select one based on its coverage, the time needed to take effect and its ease of application. For example, some disinfectants must be fully dry to achieve their maximum effect, while others work directly on or shortly after contact. Some disinfectants even have residual action after they have fully dried. It is important to ensure that you are using the correct dosage for the product to complete proper disinfection. The Center for Food Security and Public Health at Iowa State University is a great resource for obtaining a better understanding of disinfectants.
Water lines are often a frequently overlooked area of the barn in need of proper sanitation. It is a good practice to evaluate the water quality in the facility. Oftentimes, water lines are full of biofilm that harbors bacteria that can be carried from group to group, meaning that a newly weaned pig’s first drink could be full of stagnant water potentially laden with bacteria. A good practice is to purge the lines with a chlorination or peroxide product between groups — but keep in mind that this could break sediment free within the lines and potentially cause plugging. There are also safe options that can be completed when an active group is present, allowing for continual flushing of the lines while the pigs are consuming water.
Of course, other equipment in the facility could also be responsible for the presence of pathogens. To avoid tracking in pathogens from the outside world, boots should be thoroughly cleaned and disinfected before workers enter the rooms of newly weaned pigs. Gruel feeders and bowls should also be thoroughly cleaned and disinfected between groups. Mats are a great way to start pigs on solid feed, but if the mats are aging and fraying significantly, they can be difficult to disinfect effectively, making them a haven for disease. Feed carts, scoops, coveralls, hoses and even hats are examples of other items that could potentially harbor disease. Wooden surfaces are almost impossible to disinfect sufficiently and should be painted with latex paint to seal off any potential hiding spots for bacteria and coccidia.
Next, make sure you have a full understanding of the pathogens present in the facility that are contributing to the presence of diarrhea. There are three main categories of gut bugs: bacterial, viral and parasitic. Parasitic organisms can include coccidia, roundworms and whipworms. Coccidia are an uncommon cause of disease in weaned pigs, and sanitation of both the source farm and destination farms should be evaluated if this is a primary challenge. Round- and whipworm infections take some time to develop in a group and are very rare in newly weaned pigs. A proper deworming protocol will need to be put in place if these are identified as the source of the challenge.
Some examples of viral pathogens that can cause diarrhea in weaned pigs include porcine epidemic diarrhea (PED), transmissible gastroenteritis (TGE), rotavirus types A, B and C, and even porcine respiratory and reproductive syndrome (PRRS). Viral infections cannot be treated with antibiotics, so therapies are commonly aimed at keeping pigs hydrated and encouraging them to eat despite their abdominal discomfort. Prevention techniques include improving immunity in the sow to reduce shedding of the virus during lactation and the use of dry disinfectants over scouring groups to reduce chilling and lower environmental virus exposure.
Antibiotics can be used for infections that are bacterial in nature. Some common bacterial causes of diarrhea in newly weaned pigs are E. coli, Salmonella and, occasionally, Clostridium perfringens or C. difficile. Ileitis and Brachyspira infections in recently weaned pigs are very uncommon but are possible in saturated environments. If a bacterial agent is suspected to be the cause, then a sample should be collected and cultured by a veterinarian, followed by a sensitivity test to understand what antibiotics are effective against the pathogen. It is a good practice to repeat this periodically, especially in unresponsive situations, to make sure no changes have taken place within the barn or herd. Antibiotics should always be used according to the instructions of the prescribing veterinarian in order to ensure that the treatment is effective both currently and in the future. If an infection is not responsive to treatment, then the cause should be re-evaluated to make sure there is not another factor complicating the challenge. Of course, an ounce of prevention is worth a pound of cure, so good sanitation and biosecurity practices are paramount to preventing the exposure of pathogens to young pigs.
A young pig has very specific nutritional needs, and if we expect too much of them, they will often fail. A big challenge with starting pigs is making sure that they all have access to the proper diet stage. In large facilities that can take weeks to fill, the amount of starter ration that the first pigs get is often much different than the amount allowed for the last pigs. Of course, bins and feed lines should be emptied between groups, as a pig’s last diet is not fit to be the first feed a recently weaned pig will eat. Finally, animals that are not eating in the pen — either because they are sick or just slow learners — will have looser stools because of their decreased solid feed intake. These animals should be placed in a separate hospital or special-needs pen so they can receive more intensive care to get back to a full feed intake.
There are many factors to consider when evaluating the cause and treatment of diarrhea in a group of recently weaned pigs. Be careful not to fall into the trap of missing all of the influencing factors; otherwise, a small challenge could quickly become a crisis. Ask questions, make sure the environment is correct for the pigs’ group size and weight, get your veterinarian and nutritionist involved, and make sure to record your successes and failures as you go. With patience and understanding, even the biggest challenges can be overcome!