Colic in Foals
Anatomy / PedigreeMay 20th, 2020
Dr. Stuart Brown DVM from Hagyard Equine Medical Institute in Lexington Kentucky generously wrote this article on colic in foals following a number of inquiries and questions. This in-depth overview comes from his expertise in broodmare reproduction and routine primary care. Learn more about his background here
“Colic in horses, as evidenced by a wide range of causes that result in signs of abdominal discomfort, is always a daunting challenge to treat and cure, but this is especially true in young foals. Many of the symptoms we recognize in the horse often help us to characterize the nature and severity of the colic episodes that we observe. These signs may vary in the severity of their pain which may suggest the nature of the cause as in the small intestine that is often quite painful and acute in onset as opposed to the large intestine which a might be duller and more persistent as it presents. With an extensive digestive tract such as found in the horse, a multitude of opportunities present themselves to produce the signs we see as colic from infection to these different segments to mechanical obstructions in any of the parts. Oftentimes, we recognize that these symptoms in the young foal can vary when compared to the adult horse, making our role to successfully intervene even more challenging to assist them.
In particular, foals present with a number of unique challenges to diagnose and treat for colic. After birth in the early neonatal period, we are often vigilant to insure that the foal passes it’s meconuim (first intestinal contents to be expelled after delivery) as these are often firm and can result in impactions and colic, if not addressed. Many horsemen and veterinarians will provide enemas as a preventative measure that assists with expulsion of these contents as the foal adjusts to life outside the mare’s womb. When we see signs of colic in the first 24 hours of life, this is one of the areas we seek to address to insure competency and function of the foal’s digestive tract is occurring. If their is a failure of the normal expulsion of meconimun to occur, this can lead to extensive impactions of the distal intentional tract that may require surgical intervention in rare occasions. This may also occur as a result of the maladjustment syndrome we recognize after protracted delivery in which oxygen supply to the foal may be interrupted and can affect all normal organ system function, to include the gastrointestinal tract.
Additionally, we worry about normal urine production in the newborn foal and watch for the posturing reflex seen in both colts and fillies to occur. When we recognize signs of colic in this age group, we also must consider the possibility of a ruptured bladder that occasionally will occur at delivery when the foal is expelled by the mare against a baby’s full bladder. These foals may present with dull onset of abdominal pain that progresses without signs of fever. We may see them urinate abnormally small amounts with incomplete tears to the bladder wall but recognition of urine seen in the abdomen on an ultrasound examination can help us make a surgical referral to repair the bladder. We also note clinically that these cases occur more often in colts than fillies due to their longer urethra in the male.
In the first 24 hours of life, we know how critical it is for the foal to establish a bond with the mare and to establish a normal suckling reflex. This is critical to the health of the foal to ingest the nutrient rich colostrum, rich in antibodies, in its mother’s first milk after foaling to procure an established immunity for the foal. As foals are essentially born immunocompromised without antibody, they are able to absorb these proteins as antibodies for a short interval in the first 12 to 24 hours of life in most situations through a unique transfer and absorption mechanism. However, this same opportunity can allow infectious organisms to be absorbed through the gastrointestinal tract and establish infections in the foal which is worsened if the foal doses not have a chance to absorb adequate colostrum. Sometimes the establishment of an infection locally in the digestive tract of the foal can lead to abdominal signs of colic due to inflammation of the lining of the intestines and also gas formation by these organisms that cause dilation and pain in the intestinal tract. These are important for us to identify in this age group to address treatment that avoids surgical intervention. Many of these cases are diagnosed with clinical examination, ultrasound of the abdomen, and blood work results to support the foal until clinical signs resolve.
We never take surgical intervention into the abdomen lightly in any horses but especially foals. With such an extensive digestive tract, they are quite susceptible to post surgical complications and infections due to the extensive nature of the lining of their organs and abdomen with a membrane called to peritoneum. This lining is critical as a barrier of infection for their health but is also a concern in young foals as it can lead to adhesion and scar formation in the abdomen due to complications with healing after surgery of the abdomen in the foal. Thus, we are meticulous in these elements when colic signs occur in young horses to treat medically and intervene with surgical exploration when we find conditions that lead to bowel obstruction that is not resolvable. These may include strangulation or twists of the small intestine that cannot be fixed without this intervention to correct the cause of colic in some foals.
The challenges we find in examining foals for colic are greatly helped today by our improved technology and diagnostic tools. Ultrasound equipment greatly helps us assess the condition of the foal’s abdomen when presented for colic and access to diagnostic blood work is better today to support our assessments of health in these situations. Today, we are in positions to successfully intervene on behalf of the health of these foals that experience colic episodes for conditions that have existed since the domestication of the horse allowing us to save many countless cases from suffering from these challenging conditions. “