Time to Thrive: Neonatal Health Concerns
A look at health risks and survival rates among equine neonates
Never underestimate a foal’s desire or ability to survive. Although books and articles might paint a bleak picture for broodmare owners, with the goal of preparing them for the vast and varied causes of neonatal foal disease and death, a more accurate picture is actually one of success.
In fact, the phrase “Foals are programmed for survival” has been a mantra James Orsini, DVM, Dipl. ACVS, has used for years.
Orsini, an associate professor of surgery at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center, in Kennett Square, frequently cites supporting data from a group of broodmares that foaled in large pastures in Western Canada with minimal human intervention. In that study, the overall neonatal survival rate to 10 days of age was 78%, not far off from the 80-99% survival rates observed in groups of intensively managed mares and foals—think horses that are handled daily and watched carefully for signs of pending parturition (birth) or associated problems. Leading causes of death in these unmanaged foals included starvation (27%), septicemia (infection of the blood, 26%), and dystocia, or difficult birth (20%).
“These data show that even foals born under ‘rudimentary’ conditions have an excellent chance of survival during a fragile period of their lives,” says Orsini.
That said, we still need to be prepared to quickly intervene on the foal’s behalf when things do go wrong.
“The first step to success is recognizing conditions that might contribute to a foal being sick, quickly recognizing when the foal needs help, and knowing how and where to get the help they need,” says Orsini.
Here we’ll review the latest information regarding the top causes of neonatal illness, including the impact mare health has on the foal, why the foal—even though remarkably resilient—remains fragile, tips for recognizing illness, and things to keep in mind if a neonate does get sick.
Most foal losses occur in the early stages of pregnancy, referred to as early embryonic death. So when we have the finish line within our sights—usually somewhere in the third trimester of -pregnancy—we often think we’re home free. Alas, this is not always the case. Many factors contribute to neonatal loss at this stage, one of which is mare management.
“Maternal ‘mishap’ and illness, such as uterine torsion or a strangles outbreak, significantly increase the risk of foal morbidity (illness) and mortality,” says Orsini.
Other examples of goings-on with the mare that negatively impact the foal include inflammation of the fetoplacental unit (the foal and placental tissues), such as placentitis, often caused by infection and evident as vaginal/uterine discharge; colic, with or without surgery; and the hoof disease laminitis.
“One study showed that 58% of foals born to mares that suffered clinical disease during pregnancy died,” says Orsini, so promoting good health with a proper diet, routine vaccinations, and other preventive care is crucial. “Timing of mare illness during pregnancy also appears to impact foal health and survival. Many studies suggest that the earlier in gestation a problem occurs, the better the foal’s chances are for survival.”
The parturition process itself is also hard on the foal, even when it’s a completely normal delivery. Although mares can and do foal independently, implementing even minimal intervention strategies (such as being there in case a problem such as dystocia occurs) negates a large percentage of mishaps.
“Dystocia increases the risk of neonatal death by 17 times,” says Orsini. “Of the births that did not go smoothly, many were unattended.”
All in all, simply providing appropriate mare care during gestation and attending the birth improves the chances for an uneventful foaling.
Finally, mothering behavior also impacts foal survival. One example of normal maternal behavior is helping the foal stand and nurse. Consuming that first meal, the mare’s antibody-rich colostrum, is imperative for avoiding failure of passive transfer of immunity. Foals that either do not nurse or have blood IgG values (which reflect the presence of infection-fighting antibodies obtained from that colostrum meal) lower than 400 mg/dL are 63 times more likely to die than foals with IgG levels above 400 mg/dL.
Sensitive Upon Arrival
On the foal’s much-anticipated delivery, we might again feel like the battle is won. But, again, though tenacious, foals are fragile. This is partly because they are quintessential procrastinators, leaving all their final preparations to the last moment, experiencing rapid changes in every body system in the mere minutes it takes to exit the womb. John Madigan, DVM, Dipl. ACVIM/ACAW (animal welfare), professor of medicine and epidemiology at the University of California, Davis, School of Veterinary Medicine, described some of these changes during his presentation at the 2015 European Veterinary Conference Voorjaarsdagen, in Amsterdam:
- Changes in body temperature (as the foal adjusts to the environment outside the uterus), putting foals at risk of hypothermia;
- Alterations in how nutrition is delivered and metabolized, making foals susceptible to hypoglycemia (low blood sugar levels);
- A suddenly vulnerable immune system; and
- Breathing oxygen and experiencing fluctuating oxygen levels based on body position.
“One of the most important factors to consider in neonatal foals is that their condition can change far more rapidly compared to that of an adult,” he says. “While we may be able to walk a colicky mare for hours and provide intermittent relief with only an oral non-steroidal anti-inflammatory drug like Bute, this type of wait-and-see approach is not recommended when faced with a colicky foal.”
The Early Days of Life
In light of those sudden shifts, there are a few major concerns must we consider in the neonate. Orsini says the leading cause of foal death remains sepsis—a life-threatening infection of the blood that foals can develop after bacterial exposure upon entering the “real world.”
Foals come from a sterile environment (inside the placenta) and immediately encounter bacteria in the birth canal and their birthing suite—the barn or pasture. Plus, again, they are born without infection-fighting antibodies (e.g., IgG) until they ingest colostrum. This might seem like poor design but, keep in mind, the other arms of their immune systems are actually very functional, almost to the point of detriment.
“It often isn’t the bacteria that cause the biggest problem, but the foal’s response to the bacteria,” says Orsini. “Foal’s ‘do inflammation’ (mount inflammatory responses) very well, which means that they often overreact to the presence of bacteria and cause more problems in their bodies than the bacteria themselves.”
Albeit important, a detailed description of sepsis and the associated condition SIRS (systemic inflammatory response syndrome) is beyond the scope of this story (see TheHorse.com/27346 for more on this topic). Instead, let’s address other common causes of illness and loss of foal life within the first week or so of birth:
- Meconium aspiration during parturition The meconium—the foal’s first manure—essentially plugs the intestinal tract, stopping material from passing in utero. If the plug passes from the rectum too early, the foal “inhales” the material during the birthing process, potentially causing lung infection.
- Need for surgeryA ruptured bladder during the foaling process is fairly common and requires near-immediate surgical repair. Other reasons foals undergo surgery include infected umbilical remnants and colic.
- Colic Leading causes include delayed meconium passage (called impaction), lack of normal intestinal movement (ileus), and congenital abnormalities/birth defects of the gastrointestinal tract (e.g., atresia coli, or failure of the large intestine to develop properly).
- Neonatal maladjustment syndrome, or NMS This disorder was classically described as dummy foal syndrome and attributed to oxygen deprivation (hypoxia) in the brain during parturition. “Although the exact number of foals affected are not known, NMS is a common condition,” he says.
Madigan explains that altered foal behavior, failure to bond with the mare, and either delayed nursing or failure to nurse associated with this condition put the foal at risk for developing septicemia.
“Neonatal maladjustment syndrome may not be simply due to hypoxia-related brain changes but, rather, persistence of intrauterine neurosteroids that keep the foal in a sedated, sleeplike state,” he says. “In fact, many foals are now being treated in the field with a ‘squeeze’ process to mimic birth canal pressure, which may be a critical signal for transition of intrauterine physiology to extrauterine life.
“When a wandering, non-nursing and disoriented foal rapidly transitions to normal post-birth bonding and udder seeking, there is an increased chance of survival,” he continues.
Now that we know the leading causes of foal demise, it’s important to be sure we can recognize a foal in trouble; neonatal foals are odd creatures that behave quite differently from adults. Signs include:
- Altered mentation (lethargy, depression, decreasing responsiveness, failure to stand and nurse);
- Cold extremities;
- Elevated heart rate (approximately >100-140 beats/minute);
- Increased respiratory rate (>30-40 breaths/minute) or effort;
- Decreased blood glucose (<40-50 mg/dL); and
- Abnormal body temperature (either too high, above 102.5°F, or too low, less than 99°F).
Managing a sick foal can be expensive, time-consuming, and an emotional rollercoaster. Should you pursue conservative or more involved treatment? Refer him to a local hospital for intensive care or keep him at home? How will this impact the rest of his life? The list of questions racing through an owner’s head is typically extensive, and there are no easy answers.
When faced with difficult decisions managing a sick foal, consider Orsini’s insight: The survival rate of noncritical but only seriously sick, nonseptic foals is currently estimated to be 75-95%. Examples of foals falling into this category include those with meconium impaction, diarrhea, or respiratory distress, or those born premature or dysmature (born full-term with signs of prematurity), etc.
“Perhaps more amazing is that even for ‘critically ill’ foals, the survival rate is approximately 60-80% with appropriate medical care,” he says. “The classic case in this category is the septic foal.”
“These rates are remarkable, reflecting the medical advances made in neonatal care over the past several decades,” he continues. “We have come a long way, considering the survival rate of septic foals in the 1980s was only 26%.”
Based on his experience, says Madigan, “More foals are being treated in the field rather than referral hospitals with critical care capabilities largely due to the current economic climate. With recent advances in neonatal care, including the prompt recognition and aggressive intervention based on what could be wrong with the foal, many therapies are used successfully to treat ailing newborns.”
The upward surge in neonatal foal survival mirrors that of septic newborn babies, for which the survival rate was a mere 3% in 1966 but has climbed steadily to 90%.
Foaling out mares is not for the faint of heart. Even with the best of care, things can and do go wrong.
“Its important to consider all of the mare, foal, and environmental factors when assessing a newborn foal to ensure all his or her needs are met,” says Orsini.
If you are even the least bit concerned, call your veterinarian immediately: Time is life for a foal. If faced with a sick foal this season, take a deep breath, follow your veterinarian’s advice, and all the while recall the positive survival data reported by our sources. Foals are resilient and programmed for survival.
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