Performance losses associated with diarrhea are always worthy of concern, but add in today’s high feed costs and you have an extra incentive to keep the pig’s digestive tract healthy and functioning efficiently.
Since diarrhea cuts into optimum weight gain and feed efficiency, getting pigs back on track is a top priority. Pigs that are delayed in reaching optimum market weight penalize your operation not only by higher feed costs, but pigs that fall short face potential packer discounts.
Determining the causative organism is a priority before treatment begins or prevention measures can be initiated. “Based on herd history and age of pigs, many times there are some diseases that are more likely to be involved than others,” according to Alex Ramirez, DVM, Iowa State University College of Veterinary Medicine.
Start by recording each disease incidence in a barn, including age of pigs, symptoms, diagnosis, treatment used, number of pigs affected and death loss. That will help provide insight in determining a prevention strategy for the next turn.
Although you may expect to see some diarrhea or loose stools when you suspect enteric issues, you can’t just look at the pigs and know with certainty what pathogen is causing the problem. When diarrhea is present in pre-weaning pigs, Ramirez says, the most common potential causative organisms include Clostridium difficile, Clostridium perfringens Type A, Escherichia coli and rotaviruses. In the early nursery stage, rotaviruses and E. coli are more typical.
To make the correct diagnosis, Ramirez stresses the importance of submitting tissue samples for laboratory testing to ensure the right agent or agents are identified. For example, E. coli often causes scours in pigs before weaning as well as during the first two weeks after weaning. “The E. coli that causes post-weaning scours is usually a totally different strain from that causing scours in piglets in the farrowing house,” he says.
In the finishing phase, ileitis may be the leading cause of diarrhea. The organism that causes the disease, Lawsonia intracellularis, is endemic on most U.S. swine farms and can wreak havoc on finishing schedules due to the setback to average daily gain that occurs when the disease flares up. According to estimates, ileitis may cause losses of up to $5 per head.
Classical ileitis symptoms include black, tarry diarrhea, which increases as the disease becomes more severe. Economic loss is usually related to additional days to market or death loss in severe cases. “In classical ileitis where you see black, pasty diarrhea on the pigs’ backsides, death loss may reach 5 percent or more,” says Norman Hansmeyer, DVM, Winfield, Iowa. “A post-mortem examination that reveals a ‘garden hose’ gut — or thickened small intestine — also strongly suggests ileitis.”
Ileitis can lurk in herds and go unnoticed. “A certain amount of ileitis cases go unrecognized until pigs are being marketed and their average weights are down or there are too many pigs that are simply not making weight,” Hansmeyer notes. At times, a producer may see weight variations among a group of similar-age pigs, indicating that the animals harboring the organism are not keeping up with penmates.
When Hansmeyer sees this among pigs in the 120-pound to 150-pound range, he suggests submitting a fecal sample from a couple of the lighter pigs to check for the disease.
In this chronic form, you may see slightly loose stools but not the classical ileitis symptoms. Even though mortality is not as much of a factor, these animals will not perform up to par and there will still be significant economic loss. “There is likely more of this chronic ileitis out there than we realize,” Hansmeyer says.
For most enteric pathogens, key prevention practices include minimizing exposure through biosecurity and maximizing animal health through immunity and nutrition. “Vaccines help booster the immune system, but pigs need to be healthy when they receive the vaccine for best results,” according to Ramirez.
From a biosecurity standpoint, the focus must be on minimizing the introduction of new organisms. For example, management practices such as isolating incoming breeding animals for 30 days to 60 days will help minimize the spread of pathogens within a farm. Review your biosecurity plan with your herd veterinarian to be sure you’re not overlooking protocol and to ensure practices haven’t gotten lax. (For more on biosecurity, go to http://bit.ly/UPWEKx.)
Certainly when it comes to enteric diseases, it has to be a priority to thoroughly clean and disinfect facilities. That means nooks and crannies; it also means allowing time for facilities to dry completely.
Determining the time and route of exposure (infection) through a diagnostic workup will help determine the proper stage to implement prevention steps, Ramirez says. Once those diagnostic results are known, as well as an assessment of the severity of symptoms is complete, prevention measures can be put into place.
When caused by bacteria, treatment usually involves the use of antibiotics, Ramirez says. For viral diseases such as rotavirus and transmissible gastroenteritis, treatment should focus on supportive care to prevent dehydration. This might include electrolytes administered in the drinking water.
For enteric diseases that occur before weaning, vaccinating the sows can be an effective strategy. For diseases that occur post-weaning, individual pig vaccination is required. Of course, when animals are vaccinated, it’s still important to minimize pig exposure to pathogens to enhance protection. One method is to try to avoid mixing groups of pigs to reduce exposure.
While the occasional loose feces can be easy to overlook, train workers to make it a part of their daily observations. With record feed costs, it’s an especially high priority. Discussing diarrhea-prevention strategies and biosecurity measures with your veterinarian will help you keep the lid on enteric disease, and proper diagnostics will ensure that you hit the right target when needed.
Get the Jump on Ileitis
Ileitis is the most economically significant enteric disease affecting pigs, and prevention strategies generally consist of two options:
- antibiotic treatment in the feed or water
One prevention strategy often used is low-level antibiotic administered in the feed. “Some producers choose to pulse-medicate with an antibiotic,” says Norman Hansmeyer, DVM, Winfield, Iowa. “The pulse-medicating option usually begins in the post-nursery stage to help inhibit the causative organism (which is Lawsonia intracellularis).”
If there is a history of ileitis in a particular barn, it may be most effective to begin supplying medicated feed about two weeks ahead of when the disease appeared historically.
The antibiotic is then withdrawn for a period when pigs are between 60 pounds to 120 pounds, Hansmeyer says. During this time, pigs may be exposed to the bacteria which will help develop natural immunity. “Hopefully, pigs will then be less likely to break with the disease when they get older,” he adds.
“A preventative action is always cheaper and more effective than reacting to a problem that’s already surfaced,” according to Verlan Van Wyk, finishing manager for Synergy LLC, a Sully, Iowa-based finishing operation.
Van Wyk provides a medicated diet for 14 days when pigs are 7 weeks old, followed by a second pulse at 13 weeks of age. A final 14-day treatment is given when pigs are 19 weeks old. (For more, go to http://bit.ly/QUagpR.) Another option is to keep a low level of antibiotic in the feed all the way through the finishing period so the bacteria don’t have a chance to produce disease.
“With classical ileitis, which is more often seen at 200 pounds to 220 pounds and up, we use an antibiotic delivered in the water because those pigs are not eating,” Hansmeyer adds. “It’s critical that these pigs receive treatment.” When clients see the pasty, black diarrhea in these heavier animals another option is individual treatment with an injectable antibiotic.
An ileitis vaccine also is available for prevention. Hansmeyer urges producers who have ongoing trouble with ileitis to vaccinate for the disease in the nursery at 5 to 6 weeks of age. “It takes a period of time to develop good immunity with the vaccine, so we like to see it administered before the pig is subjected to the stress which can accompany the move to a finishing area,” he adds.