Red flags in foals one to four months old demand immediate veterinary attention

by Denise Steffanus

MOST FOALS emerge from the first delicate weeks of life as a neonate in good health, but youngsters between one and four months old should not be considered out of danger. Symptoms that are not regarded as serious in weanlings could indicate the onset of illness in younger foals that might cause their health to deteriorate rapidly, even ones that appear to be robust.

According to Harold McKenzie III, D.V.M., M.S., a board-certified veterinary internal medicine specialist at the Marion duPont Scott Equine Medical Center in Leesburg, Virginia, every foal owner and broodmare manager should recognize six symptoms in foals that require immediate attention. Those red flags are depression or lethargy; decreased interest in nursing; fever; nasal discharge; diarrhea; and coughing.

Any one or more of these symptoms is a cue to monitor the foal's health closely and consult a veterinarian.

What they mean

Here is a closer look at each symptom:

•Depression or lethargy. Just as it is evident a normally active toddler is not feeling well when he uncharacteristically lies on the couch all day, a foal that appears depressed or lethargic probably is not feeling well enough to romp and play.

•Decreased interest in nursing. A foal may show a decreased interest in nursing because of a rising temperature, a gastrointestinal problem, or simply because his low energy level might incline him to remain lying rather than stand and nurse.

•Fever. "Fever can mean a lot of things," McKenzie said. "It's an important clue that the foal isn't normal."

A foal's normal temperature is 101¡, and a variation of more than one-half a degree either up or down warrants close attention. A drop in temperature might be more cause for concern than a rise because it can mean the foal's immune system is not responding appropriately to a challenge.

"In a perfect world, taking the foal's temperature every day is not a bad idea," McKenzie said. "The farms I've worked with where they do that usually catch things early."

•Nasal discharge. Nasal discharge occurs when antibodies respond to an upper respiratory pathogen. An occasional runny nose in a bright and playful foal is normal, and the discharge should be thin and watery. A persistent discharge warrants a closer look, especially if it is thick or discolored.

•Diarrhea. Diarrhea in foals is always a cause for immediate attention, because if it is allowed to persist, the foal quickly will become dehydrated and might acquire an electrolyte imbalance that will depress the immune response. Infection, ulcers, digestive disturbances, and parasites can cause diarrhea.

•Coughing. Coughing is the body's way of clearing the airway of mucus or other foreign material. A frequent cough often is the first outward sign of pneumonia or the respiratory form of herpesvirus.

Pneumonia

In McKenzie's opinion, one of the biggest concerns in foals is pneumonia, which also might have lasting effects that can compromise a horse's athletic performance as an adult. Fever, coughing, nasal discharge, and lethargy are some of its symptoms.

"Bacterial pneumonia is a fairly common problem in foals," McKenzie said. "Monitoring temperature and watching for any evidence of respiratory signs--coughing, nasal discharge, labored breathing--those are all important things to keep an eye on a daily basis."

Pneumonia caused by Rhodococcus equi is particularly deadly, but its early symptoms can be subtle enough to go unnoticed for months until the infection has abscessed the foal's lungs.

"You can monitor a couple things on a herd basis to try to pick out the foals that are developing Rhodococcal pneumonia," McKenzie said. "Fever is one, and big farms that have issues with this type of pneumonia also will monitor complete blood counts [CBCs]. If you have a foal whose CBC shows a very high white blood cell count or fibrinogen level, there is almost nothing else that's going to cause that other than Rhodococcal pneumonia."

Because R. equi is a bacterial infection, antibiotics are effective in treating it, but only if it is diagnosed early.

"The sooner treatment is instituted, the better," McKenzie said. "The more advanced it is before you start treatment, the less likely the foal is to survive."

Another disease that produces respiratory symptoms in foals is equine herpesvirus, and McKenzie said he has seen some cases in three- to four-month-old foals at the duPont Scott Center. Most well-managed mares are inoculated against herpesvirus, or equine rhinopneumonitis, in the fifth, seventh, and ninth months of pregnancy so immunity to the disease is passed to the foal in their colostrum, or first milk. But three to four months of age is when maternal antibodies in the foal decline and could allow it to be susceptible to the disease.

"In older foals, herpesvirus is generally in the respiratory form, not the neurological form," McKenzie said. "There's a window around that three-to-four-months-of-age period, when under even the best management scheme, foals are going to be susceptible, whether the mare was vaccinated or not."

With supportive care consisting of anti-inflammatory drugs, good nutrition, and adequate hydration, most foals recover well.

Gastrointestinal problems

Diarrhea often is the first sign of gastrointestinal disease, including gastric ulcers, and McKenzie said his clinic has seen an increase in admissions of foals with diarrhea.

"I don't think the problem is any more common," he said, "but I think what has happened is that people have become more aware of the potential for a really serious deterioration or death if they don't treat them aggressively. So we get them earlier now."

McKenzie said foals with diarrhea account for as much as 50% of those that come into the duPont Scott Center.

"Many of those foals will become depressed and will stop eating before the diarrhea breaks out," he said. "A fair number of them actually will be colicky because of the cramping from the gas and fluid. Close to half the ones that come into our clinic have a history of colic in the prior 24 hours. Some of them don't have diarrhea before they get here; they come in as a colic case, and within an hour or two of walking in the door, they have profuse diarrhea."

McKenzie differentiated between diarrhea in older foals that should be cause for concern and diarrhea in foals about ten days old, which occurs about the same time as the dam's foal heat.

"Typically, foals with what we call foal-heat diarrhea are not sick," McKenzie said. "They're bright, alert, and nursing well. They have normal temperatures, and they're not colicky. Also, there's that age window. So, if you have a month-old foal, you know it's not foal-heat diarrhea."

McKenzie said most foals with diarrhea that are presented for treatment at the duPont Scott Center are clinically ill.

"They are depressed, off the suck, may or may not have a fever, and they are becoming dehydrated," he said. But with any foal diarrhea, McKenzie said the potential exists for the condition to become a serious problem, so he urges owners and managers to err on the safe side.

"My recommendation to farm managers is to assume the worst," he said. "If there is any sign of depression, or if that foal is not coping with the diarrhea--if it is getting dehydrated, dull, and losing interest in the mare--then you potentially have a very serious condition."

Gastric ulcers

Being in a referral hospital, McKenzie and his colleagues see only foals whose illness cannot be managed effectively on the farm by the referring veterinarian. So the foals with ulcers that come in for treatment typically are a challenge. Often, classic signs of ulcers, such as diarrhea and teeth-grinding, are not evident.

"We see a number of cases every year of profound, severe gastric ulceration in foals that require surgery and may even result in death," he said. "I've had a few cases in the past couple years that have [arrived at the clinic] dead or dying from perforating gastric ulcers.

"The problem with these foals is their symptoms are pretty subtle. They are not showing you classic colicky signs. But they are not thrifty, and they are not eating well."

McKenzie said some of these foals can have a condition common in humans called GERD, or gastroesophageal reflux disease, which causes them to burp.

"Many of these severely affected foals actually will be burping," he said, "and it's because they have ulcers going up into their esophagus, so they are refluxing with gas and fluid coming up into their esophagus. I've had four or five in the past couple years that have come in with the primary complaint being that it was a dull foal, not very thrifty, and it kept burping. And these foals had horrendous involvement of the stomach."

McKenzie said that in many of these cases of severe ulceration down deep in the stomach, the foal had been ill for several weeks but even well-managed farms did not recognize the subtle symptoms.

Because many of McKenzie's clients realize the potentially serious nature of gastric ulcers in foals, he said a lot of them start foals considered to be at risk for gastric ulcers on a regimen of UlcerGard, a Merial Ltd. product that has been approved by the United States Food and Drug Administration for prevention of ulcers in horses. UlcerGard is a one-quarter dose, over-the-counter version of the prescription GastroGard that is available through veterinarians. Both UlcerGard and GastroGard contain omeprazole, considered the gold standard for prevention and treatment of ulcers.

Be vigilant

Most good horsemen know you have to lay hands on a horse at least once a day to ensure it is in good health. For foals, this means getting them up in the stall, checking them over for cuts and other injuries, making sure their eyes are bright and their noses are not running, taking their temperatures to assure they do not have fevers, and then observing them to ensure they are nursing and creep feeding, if they are offered grain.

Besides catching early symptoms of illness, foals benefit from regular handling, which will make them easier to break and train later in life.

Denise Steffanus is a contributing editor of Thoroughbred Times who writes frequently on veterinary and farm management topics.