Getting weaned pigs on feed and growing efficiently is a top priority. But obstacles such as disease, inexperienced crews, the animal’s feed acceptance, facilities and feeders often present challenges in this critical growth stage.

Now, a new challenge is receiving more attention. In nurseries and wean-to-finish barns, peri-weaning failure to thrive syndrome, known as PFTS, is causing some mysterious pig losses and is confounding producers.
In some production systems, the troubling syndrome is affecting up to 5 percent to 7 percent of weaned pigs. Although it’s not a new syndrome, PFTS is receiving additional research focus recently in an attempt to better describe the problem and alert producers to the symptoms.

Marked by a slow deterioration from the time pigs arrive at a nursery or wean-to-finish facility, PFTS pigs simply do not eat, and as a result, they fail to grow.

Unfortunately, the syndrome targets the more robust weanlings. “We see the bigger, better pigs affected,” says Steve Henry, DVM, Abilene Animal Hospital, Abilene, Kan. “The affected pigs often become flat-sided, gaunt and do not respond to special intervention efforts such as supplements, gruels, electrolytes or other efforts.”

While incidence of the syndrome varies from one pig group to the next, one thing is usually constant — after about five days of symptoms, affected pigs die.

Henry has described four stages often encountered with PFTS pigs:

1. Active phase: Pigs are alert and react normally to stimulus but do not eat. Water consumption usually remains normal; elevated temperatures are not seen. Pigs generally interact normally with penmates.
2. Chomping phase: Pigs become more depressed and exhibit oral chomping or chewing mouth movements for reasons that are not clear. Pigs in this phase are less active and less responsive to stimuli.
3. Standing phase: Pigs are inactive. Some are immobile, with drooping heads. This phase usually occurs 10 days to 12 days after weaning.
4. Terminal phase: This final phase is characterized by increasing weakness, dehydration and death.

The weakened pig is most vulnerable to infection by bacteria that are normally present. “Haemophilus, Streptococcus, Salmonella and other common bacteria cause damage in affected pigs,” Henry says. These infections further complicate the animal’s declining health status.

PFTS risk factors are thought to center around stressors at weaning and may include other pre-weaning factors. “These can include vaccination and rough handling,” Henry says. In addition, when a facility is filled during a four- to five-day period, the last pigs to arrive may be at higher risk.

Incidence does not appear to be seasonal in nature, according to Henry, nor does he see a relationship to transport time. “We suspect this may be a viral disease, but it doesn’t appear to be spreading from herd to herd. Plus, it can come and go within a herd.”

Close observation of newly arrived pigs is key to identifying affected animals, says Mark Whitney, University of Minnesota Extension swine program leader.  “When filling a nursery or wean/finish barn, check pigs closely on the second and third days of placement for any signs of lethargy or gauntness,” Whitney says. “Have a treatment pen available, and move any identified pigs to the treatment pen for additional care. Provide electrolytes and use highly palatable and digestible diets, preferably in gruel or gel form.”

PFTS has been around for some time, but it now seems to be more persistent and more frequently recognized, Henry says. Researchers at several universities, including Kansas State University, Iowa State University, University of Saskatchewan and University of Minnesota, are studying the syndrome in an attempt to uncover answers.

 “When we search for known pathogens or syndromes (in affected pigs), we don’t find anything,” says Darin Madson, DVM, veterinary diagnostic laboratory, Iowa State University. “At this point, we’re planning more in-depth diagnostic work with a goal of developing a more comprehensive set of risk factors.”

Madson explains that in the past, PFTS may have been attributed to the presence of concurrent swine diseases in a herd, such as porcine reproductive and respiratory syndrome or porcine circovirus disease. “We’re still seeing PFTS even in herds that have PRRS and PCV2 under control, so we can’t blame it on them anymore,” he adds.

As more information surfaces on PFTS and more pigs are examined, Madson and other researchers will collect data on a long list of factors in an attempt to define risks that may play a role. Madson wants to explore physiological functions going on with the PFTS pigs. “Factors such as stress and lack of certain nutrients can throw off a pig’s physiological function which can make it unable to keep up with the group,” he notes.

Researchers will continue a systematic approach in studying PFTS and they expect more answers to emerge. “As we compile more case histories, nutrition profiles and management details, we will start getting a clearer picture on risk factors that lead to this syndrome,” Madson says.

Henry is closely involved with the researchers and believes answers will be forthcoming.  “We hope to define PFTS more clearly, sort it out and determine what it is as well as what it’s not,” he says. “While it’s not the scourge of the pork industry, we need answers for producers.”

The only intervention so far is to remove as much stress as possible from the peri-weaning period, Henry says.

If some of the symptoms sound familiar, take action now to reduce stress on weaned pigs. (See sidebar.) Even if you haven’t seen any PFTS symptoms, stress reduction could help minimize the potential of encountering the mystery syndrome in your operation.