Managing Severe Colic in the Field (AAEP 2011)

According to a recent poll on TheHorse.com, nearly 49% of respondents named colic as their most feared horse health emergency, and for a good reason. While some cases resolve without incident, others prove deadly. Colic surgery is an option for owners in some severe colic cases, but what if referral isn't possible?

David Freeman, MVB, PhD, Dipl. ACVS, professor and interim chair of Large Animal Surgery at the University of Florida, provided some insight on treating severe cases in the field during a presentation at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas.

Decisions, Decisions

Freeman began by discussing some considerations and decisions owners should make with their veterinarians prior to a colic emergency arising.

First, he noted, it must be determined why referral is not an option in a severe colic situation. He gave four examples of common answers:

  1. "Colic surgery is rarely successful."
  2. "This is a pregnant mare, and it will be impossible to save the mare and the foal."
  3. "This is an old horse, and old horses do not handle colic surgery well."
  4. "This horse is much loved and valued, but we cannot justify spending the money on colic surgery in our present financial circumstances."

"Answers 1 to 3 are simply untrue," Freeman said. "Answer 4 is a reality … even in a good economic climate, one must decide which horses in the barn warrant colic surgery and which ones do not.”

Horse owners need to make another set of decisions once a horse suffers a serious bout of colic, he said, considering the following:

  • "How much am I prepared to spend? What is my financial limit on this horse?” (Freeman cautioned that nonsurgical treatment in the field can easily approach the same cost as nonsurgical treatment at referral hospitals as a result of farm calls, drugs, and intravenous fluids; surgical treatment at a referral hospital typically remains a pricier option.)
  • "How much of my time am I prepared to commit to around-the-clock monitoring and care?"
  • "Can I handle watching a horse suffer through disease?"
  • "Will I change my mind or stay the course?” (Freeman noted this happens when an owner opts for at-home treatment and then decides to refer when it is too late.)

If the owner is prepared to commit the appropriate amounts of time, money, and emotional strain to at-home colic treatment, therapy can begin. If the owner questions any of the aforementioned issues and the colic is serious enough, consider euthanasia, he noted.

Also, the attending veterinarian must consider whether his or her practice has the time and resources to devote to around-the-clock care; the diagnostic and treatment abilities to support the case; and the ability to watch the horse suffer at times during treatment.

Euthanasia Guidelines

Freeman explained several indicators that euthanasia is the best or only option for a horse. However, he added, none of these should be considered on its own without regard for all other findings:

  • A heart rate persistently elevated above 60 beats per minute;
  • Red, congested mucous membranes;
  • Persistently absent gut sounds;
  • Moderate to severe and worsening abdominal distension (swelling);
  • High volumes of or persistent gastric reflux; and
  • Moderate to severe persistent pain.

"Failure to respond to analgesics or recurrence of pain after analgesics should be considered an indication for surgery or euthanasia," he added.

Taking into consideration these combinations of clinical signs can help guide a veterinarian in determining when a horse likely won't recover from colic and euthanasia is the most humane option, he noted.

Diagnostics in the Field

In combination with clinical signs, there are a number of diagnostic tools veterinarians treating colic in the field can use, Freeman said.

A simple rectal examination can provide veterinarians with useful information. He said the procedure should be repeated because veterinarians can discover by feel some life-threatening changes over time. This procedure is especially useful for detecting small intestinal distension, tight colonic bands, and impactions, and some findings can support a decision for euthanasia.

Freeman noted that abdominal ultrasound can be useful for diagnosing a number of ailments including:

  • Intestinal strangulation;
  • Peritonitis (inflammation of the membrane lining the abdomen);
  • Intussusceptions (when the gut telescopes back into itself);
  • Large colon displacements and volvulus (twist);
  • Renosplenic entrapment of the large colon (when the large intestine slips up and over the ligament between the left kidney and spleen);
  • Inguinal and scrotal hernias; and
  • Abdominal tumors.

He cautioned, however, that operator inexperience could play a role in achieving an accurate diagnosis. Abdominal ultrasounds can also help a veterinarian decide for or against euthanasia.

Finally, Freeman discussed the use of belly taps (the abdominocentesis procedure). While the procedure can yield useful information about the nature of the colic, belly taps require laboratory analysis to produce results for interpretation. If the time and technology is available, belly taps can support a decision for or against euthanasia, as well. But they can also be misleading, he advised.

A Grim Prognosis

Not surprisingly, each case is different and assessment will yield an individual prognosis, Freeman said. There are, however, several types of colic that typically result in death or euthanasia if surgery or intensive hospital care is not provided.

Impaction with a large enterolith (an intestinal stone—these can vary widely in size) is one cause of colic that is always surgical, Freeman said.

Strangulating lipomas are fatty tumors on a stalk that strangle the small intestine and often prove fatal, Freeman said. These are most commonly found in horses older than 10 years and often present with variable pain and small intestinal distension. Freeman noted that any old horse with severe colic should be suspected of having a strangulating lipoma; in these cases, euthanasia could be the most humane choice if surgery is not an option, he added.

Epiploic foramen entrapments many times result in death or euthanasia in field settings. This condition—in which a section of small intestine threads itself through the epiploic foramen (a narrow opening connecting the two sacs of the abdominal cavity) and becomes trapped—is commonly found in horses that crib; however, the reason for this remains unclear.

Uterine tears occur most commonly a few days post-foaling, he said, and are a known risk factor for developing peritonitis. While some uterine tears can resolve without issue, severe tears are indicators for either surgery or euthanasia.

Uterine torsions (twists) also are cause for concern in broodmares. These typically occur in late gestation and are a "strong indicator for euthanasia if surgery is not an option and rolling the anesthetized horse is unsuccessful," Freeman said

Finally, he noted that some fecaliths—hard concentrations of ingesta in the digestive tract—do not respond to medical treatment. Most commonly found in Miniature Horses, ponies, and foals, fecaliths firmly impacted in the small colon and nonresponsive to medical treatment must be removed surgically or the animal should be euthanized.

Take-Home Message

Managing a serious colic situation without the option of referral can be a difficult scenario. Horse owners should be prepared for such an event, knowing what will work best for them, their family, and their horse. In addition, calling a veterinarian early in a colic episode might increase a horse’s chances of a full recovery.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.

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