Colicky Foals: Diagnostics and Decision-Making
Foals’ size and fragility present unique diagnostic and treatment challenges, and their clinical signs and vets' diagnostic techniques might differ from those of the typical colic case.
Photo: Anne M. Eberhardt/The Horse
Foals’ size and fragility present unique diagnostic and treatment challenges in the face of colic. Clinical signs and diagnostic techniques might differ from those of the typical colic case.
At the American Association of Equine Practitioners’ Focus on Colic, held July 16-18, 2017, in Lexington, Kentucky, Samuel Hurcombe, BSc, BVMS (Hons), MS, Dipl. ACVIM, ACVECC, reviewed with attendees how to address these young patients.
The No. 1 cause of colic in neonates is meconium (the foal’s first manure) impaction, he said. Other types of colic veterinarians commonly report in foals include hernias, enteritis/colitis, uroabdomen (urine in the abdomen), gastric ulcerative disease, small intestine volvulus (twist), intestinal adhesions, and congenital abnormalities. Less commonly do they see large colon disease such as displacements or volvulus, he said.
Specific challenges veterinarians face when managing a colicky foal include:
- Small patient size;
- Types of lesions—Foals are more at risk of congenital issues;
- Co-morbidities—“Foals with colic often have a concurrent disease process, such as sepsis, neonatal maladjustment syndrome (aka dummy foals), prematurity/dysmaturity, dehydration, or failure of passive transfer,” said Hurcombe; and
- Metabolic needs, because you don’t want to withhold feed from a colicking foal as you would an adult.
When a foal presents with colic signs, Hurcombe said the veterinarian should make immediate note of the foal’s signalment (breed, sex, etc.) and history.
For instance, some lesions are overrepresented in some breeds. Hurcombe said that, in his experience, draft horses, Tennessee Walking Horses, and Standardbreds are more likely to develop inguinal or scrotal hernias than are other breeds. There’s also the genetic disease factor to consider, such as Paints’ tendency to produce lethal white foals.
On the gender side, veterinarians should keep in mind that congenital bladder rupture is more common in colts, said Hurcombe. And some study results show fillies to be more at risk of meconium impaction.
When taking the foal’s history, important information includes the mare’s health, whether she had a dystocia (difficult birth), parturition details, housing conditions, and history of disease on the farm.
“These are very important in determining risk for infectious disease (which can cause pain in foals with enteritis that manifests as colic), in particular,” he said.
Signs of colic in foals differ from those in adult horses and include lying on their back, rolling from side to side, decreased nursing, changes in abdominal contour, bruxism (teeth grinding), sudden decreased urine production, and postural changes such as back-arching and tail-flagging.
“Pain alone is very unspecific and is not really good at delineating medical vs. surgical colic,” in these horses, said Hurcombe.
He then listed the veterinarian’s diagnostic options and how to perform them.
Physical exam After administering sedatives and/or analgesics (pain-relievers), the veterinarian can gather basic information such as:
- Temperature, pulse, and respiration;
- Perfusion (the cardiovascular system’s status and functionality) assessment, “because when foals crash, they crash quickly,” said Hurcombe;
- Pain levels;
- Abdominal distention, because foals with meconium impaction will become increasingly distended. “Using a measuring tape around the abdomen, take the circumference every hour or so,” he said; and
- Visual assessment of structures such as the scrotum and umbilicus.
Nasogastric intubation This step in the foal’s examination is essential, said Hurcombe, but requires patience—collecting gastric contents from foals is more difficult than in adult horses.
“Given their size, smaller lubricated tubes are required to avoid unnecessary nasopharyngeal and esophageal trauma,” he said. “A stallion urinary catheter works well in most neonatal foals.”
Digital exam Due to the foal’s size, the veterinarian will need to use a well-lubricated gloved finger (and probably sedation) to perform a rectal exam. This step can help detect impacted meconium.
Abdominal ultrasound This tool is extremely useful for making a diagnosis in foals, in particular. “The small size, thin body wall, and thin haircoat make the utility of this technology high for determining the location of the lesions, presence of distention, thickness of visceral wall, peritoneal effusion, or structural abnormalities,” said Hurcombe.
Abdominal radiography (X rays) Similarly, radiographs are far more useful in foals than in adults and can help the veterinarian determine the affected anatomical region in the case of an obstruction, among other things.
Abdominocentesis This procedure—a belly tap to sample abdominal fluid--can be performed with the foal standing or lying down, with or without ultrasound guidance, and doesn’t differ much from that of adults. Foal cell counts, protein levels, etc., however, are going to be different from adults’, Hurcombe cautioned.
Gastroscopy Veterinarians can easily diagnose gastric ulcerative disease and mass lesions by viewing the foal’s stomach through a camera passed through the nostril (endoscopy).
“For neonatal foals, a 1-meter scope is usually long enough to assess the esophagus, stomach, and pyloric outflow tract,” said Hurcombe. “A small outer diameter human pediatric endoscope may be required in Miniature foals.”
If the foal requires more advanced diagnostics than the treating veterinarian can provide, is in severe pain, or has concurrent sepsis or metabolic problems, Hurcombe recommended referring it to an equine hospital or specialist.
Based on the literature, neonates have a worse prognosis for survival from colic surgery than older foals and adult horses, said Hurcombe. This can be attributed to their increased risk of intestinal adhesions, their delicate tissues, and their complicated postoperative care.
Ultimately, said Hurcombe, prognosis is lesion-dependent. “It’s excellent for meconium impactions and other medical colics without concurrent disease,” he said. “It’s good for simple obstructions or impactions and decreases with sepsis. Small intestine lesions have a guarded long-term prognosis.”
Indicators to go to surgery can include:
- Persistent pain that’s unresponsive to analgesics;
- Persistent tachycardia (rapid heart rate);
- Progressive abdominal distention;
- Increased peritoneal (abdominal) fluid protein or cell counts;
- Serosanguinous (reddish-orange) peritoneal fluid;
- Diagnostic evidence of an obstruction; and
- Worsening clinical signs despite medical management.
Hurcombe recommended proceeding only if the owner is aware of the benefits, risks, and prognosis of surgery.
About the Author
Alexandra Beckstett, Managing Editor of The Horse and a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as Assistant Editor of its book division, Eclipse Press, before joining The Horse.
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