Jeremy Pittman says it's been a "nagging" cause of scours his entire career in swine medicine. Historically, it's an indicator of poor management, but Amber Stricker says the last five years she has been seeing it more commonly in well-managed commercial farms.

It is coccidiosis, and while it is often placed lower on the list of swine enteric diseases, and diseases in general, both veterinarians say they have seen the coccidia parasites play a major role in increasing morbidity and poor weight gain in suckling pigs, nurseries and wean-to-finish.

"In my experience, I've seen pretty high morbidity, up to 90%, but low mortality and very few cases that I have pigs actually die from it," says Stricker, a veterinarian with Suidae Health and Production and based in St. Ansgar, Iowa. "It's more likely they're euthanized because they failed to make weight at weaning, and it builds up over time in the environment, especially if there is no treatment or sanitation intervention."

"I think the recent interest in coccidiosis, specifically for us, has one been focused around the importance of wean weight and as we've changed contracts and how we would pay contract growers based on a weaned pig, weight becomes more important," says Pittman, a staff veterinarian for Smithfield Hog Production — North Region, who oversees 133,000 sows farrow-to-finish in North Carolina and Virginia. "A lot of that is also a large move to wean-to-finish, particularly in the operations that I work in, where weight of that weaned pig at placement is highly correlated to successful growth and survivability of that pig."

Pittman and Stricker were invited to share their experience with coccidiosis during the co-sponsored Swine Health Information Center and American Association of Swine Veterinarians' webinar, "Coccidiosis: Relearning Old Lessons."

Mostly recognized for its tell-tale signs of pasty yellow scours, "toothpaste-like" fecal consistency and greasy litters, coccidiosis starts in pigs around 7 to 14 days of age. The disease will continue to populate within the pen over that time, and then over a room at about 10 or 14 days of age, as more and more pigs are affected. It can persist up to weaning. Some litters may stop scouring or stop showing the pasty stool, but others will continue to display symptoms all the way up to the point of weaning, and into post-placement in a nursery or wean-to-finish.

"For us, the biggest impact is at the sow farm level, it's at the piglet level," Pittman says. "Obviously, those pigs are very young, and are much more susceptible to enteric diseases, but we still see challenges in the nursery or post-weaning phase and wean-to-finish, and a lot of times we may see that complicated with other diseases, particularly post-weaning E. coli diarrhea."

Pittman says weight gain has been the biggest metric impacted by coccidiosis. "There's an increased standard deviation of the litter weight, an increased number of bottom-end pigs and pigs may not be accepted downstream and morbidity is much more of a concern than mortality. There is not generally a lot of mortality associated with coccidiosis, unless you have some sort of a co-infection, something like a clostridium early on, or some other disease challenges."

Stricker says she typically traces post-weaning coccidiosis to sow farm origin, but occasionally they have suspected contaminated sites from previous groups that have been positive, especially on concrete, slatted, nursery barns.

"It's usually pretty self-limiting post-weaning. I've rarely ever had to treat it. Once in a while, I may cut open a severely affected pig where you'll see chronic lesions, but typically it just clears up on its own," Stricker says. "The biggest thing is if there's a co-morbidity with it, like salmonella, that complicates the ability of the pig to transition onto feed and gain weight the first couple of weeks post-weaning."

Getting a sample submission is also difficult. While transient shedding makes diagnosis challenging, fresh feces collected on farm is the most reliable. Stricker details one experience, while working on a research project, where she took pigs clinically affected with coccidiosis, collected fecal material via direct catch and sent the samples to a research facility for further evaluation. Meanwhile, she conducted a fecal float on the fecal samples collected prior to shipping the pigs and found a massive amount of coccidia. One day later, the research facility reported back that the pigs appeared to be negative as they had been unable to find any coccidia from the pigs she had just collected oocysts from.

"That was just evidence for me that it really is a transient bug that is shedding one day and not the next, and so to increase your chance of obtaining a positive diagnosis it may require that you go back to the same pigs that you tested and test a week later," Stricker says.

Both veterinarians say with limited and costly treatment options, as well as short supply of one effective product, Marquis paste (an antiprotozoal oral for horses), both have had to rely on environmental decontamination protocols, such as degreasers, diluted bleach, lime wash and concrete or deck sealer.

"This is a fecal-oral transmitted disease, and it also has a parasitic type nature to it. Any residual organic material from one litter to the next litter is important, and so anything that makes it difficult to clean this residual organic material is going to increase your risk factor," Pittman says. "Two, anything that allows the buildup of manure over time is going to increase your risk factor. One of the biggest ones we see is flooring type with plastic flooring being much bigger risk than something like woven wire, and then even more so than tri-bar, and the reason for this is there's an increased amount of nooks and crannies, chips, cuts within the plastic square edges, that are difficult to power wash and get organic material clean from. It becomes really important that the flooring types that you utilize, reflect the amount of sanitation or the type of sanitation that you put into it."

What is the cost of the disease? Pittman says while there is data internationally, there is not much in the United States on what the cost of coccidiosis is, both in morbidity and weight gain.

"I think it's important for us as an industry to understand what's the cost of the diseases, so that one, we can recognize what the impact of that is," Pittman says. "Two, it can drive funds for research, for the updated research that needs to be done and then also it provides companies, a market interest, if they want to bring a product to the market in the U.S., and what that potential market share would be, and the value of the product."