Medical Colic Management What to Know
When faced with a colicking horse, especially one in a great deal of pain, you might not be in the frame of mind to ask questions and learn as your veterinarian treats your horse—and understandably so! But do you know why the vet puts a tube down your horse’s nose? Or why he chose one pain reliever over another?
The goal of treating colic in the field centres around breaking the pain cycle associated with the abdominal insult and re-establishing proper gastrointestinal function.While it might sound like a fairly straightforward task, it’s often a more complex endeavour. Medical therapy includes:
• Taking steps to relieve pain; • Administering laxatives and/or cathartics; • Giving oral or intravenous (IV) fluids; • Managing endotoxemia, if present; and • Providing nutritional management
The first steps to helping relieve a colicking horse’s pain are to administer analgesics (pain relief) and insert a nasogastric tube to decompress (or remove fluid and gas from) the stomach. “Flunixin” is probably the most commonly used analgesic for treatment of the acute abdomen. It has excellent visceral analgesic (abdominal-pain-relieving) properties with an onset of action of 20 to 30 minutes.
Another benefit is that a single dose of flunixin generally will not mask a surgical lesion for an extended period of time.
If the horse’s pain is not alleviated by a full dose of flunixin within 30 minutes, do not give additional doses!! Rather consider referring the patient to a hospital, as the lack of response to analgesics is often indicative of a surgical lesion or a severe colic that will require intensive monitoring and supportive care. Administering sedation with or without butorphanol might provide some additional temporary pain relief while transporting the horse.
In many colic cases being treated in the field, the veterinarian will administer a laxative in hopes of increasing water content in the gastrointestinal tract, softening ingesta (ingested feed) and getting the gut moving again. Veterinarians turn to laxatives most commonly in cases of cecum, large colon, and small colon impactions.
Paraffin oil is useful for monitoring intestinal transit time and can help encourage ingesta to move once the impaction begins to resolve.
A common used laxative is paraffin oil. While this product was long considered the laxative of choice for impactions, research has shown that it’s not as effective at breaking blockages down as once thought. Mineral oil is useful for monitoring intestinal transit time (see how long it takes the oily droppings to emerge) and can help encourage ingesta to move once the impaction begins to resolve, but “it is not useful to penetrate and hydrate the primary impaction.
Horses’ gastrointestinal tracts must be well-hydrated to function properly. So, not surprisingly, one key goal of treating colic is to ensure the patient isn’t—or if he is, doesn’t remain—dehydrated.Veterinarians can administer fluids intravenously or directly into the horse’s stomach using a nasogastric tube. When administering intravenous fluids, a balanced electrolyte solution is used to help maintain intravascular fluid volume (the volume of fluid in the blood in a horse's circulatory system).Horses experiencing acute abdominal pain may require fluids for rehydration (to replace fluids lost to excessive sweating, diarrhoea, or reduced oral intake), ongoing fluid loss (due to continual reflux or diarrhoea), or to replace fluid lost during normal body processes (the normal maintenance fluid requirements).Researchers have determined that nasogastric administration of fluid—regardless of what type—can help encourage colonic motility. They attribute this phenomenon to stimulation of the gastrocolic reflex (one of the physiologic reflexes that controls gastrointestinal tract motility).
In some cases, colicky horses develop endotoxemia, a condition in which Gram-negative bacterial toxins cross the intestinal wall and enter the bloodstream, potentially leading to serious complications such as shock, laminitis, organ failure, and death.
Symptoms of this condition include : - Depression - Lethargy - Rise in pulse rate (in excess of 80BPM) - Dark purple mucous membranes
During cases of endotoxemia, horses must be treated immediately for it to have any success. There are several courses of treatment and supportive care including intensive antibiotics and IV fluid therapy to help maintain hydration and support the cardovascular system. Plasma transfusions are also sometimes used.
Finally, your veterinarian will likely give you instructions on how to manage a colicky horse’s nutrition for a period following the episode.
Horses demonstrating abdominal pain should have hay and grain withheld for 12 to 18 hours. If they do not have gastric reflux, they should be allowed free choice water and have access to trace mineral salt.
If the horse responds favorably to treatment, it can return to a normal diet gradually over the next 24 to 48 hours. It is recommended to feed moist bran or senior feed and/or grass initially before transitioning back to the horse’s normal hay and grain.
Horses being referred for possible exploratory surgery should not be fed during transport to the referral facility.
Horses in severe and unrelenting pain that has little or no response to analgesic therapy should be referred for further evaluation.
The Decision to Refer
Try as they might, veterinarians can’t manage all colic episodes in the field. Some cases are too severe to correct without constant monitoring, treatment, and/or surgery.
Severe and unrelenting abdominal pain that has little or no response to analgesic therapy; • Abnormal findings on rectal or abdominal ultrasound examination; • A persistently increased heart rate; • Substantial quantities of gastric reflux and/or a change in the nature of the gastric reflux; • Serosanguinous abdominal fluid with increased protein levels and nucleated cell count; and • A generally deteriorating condition (we want to refer before we get to this point, he stressed).
However the decision to refer a horse for surgery isn’t always clear-cut.
The availability of adequate transportation and the distance to the nearest referral facility must be taken into consideration when contemplating transport to a referral hospital. For example, a veterinarian might be able treat and evaluate a horse in the field for a longer period of time if that animal resides within 15 or 20 minutes of a referral hospital. That is drastically different, however, if the horse lives more than one to two hours away from a hospital. In these instances he strongly encourages early referral. Certain types of colic can “result in irreversible deterioration and necrosis of the intestine within three to four hours,” Mueller said. “If your clinical intuition even hints to the necessity of referral, the owners should be instructed to make tentative arrangements for transportation should the need arise.
“Client satisfaction is much more likely if you refer a horse for medical or surgical treatment in which the horse experiences a so-called ‘trailer-ride cure’ despite the distance traveled, verses either arriving dead or having to be euthanized because of the extreme severity, duration, and extent of the condition,” potentially due to a delay in the referral process, he stressed.
A veterinarian has specific goals in mind when he or she arrives to treat a colic in the field which centre on relieving pain and re-establishing proper gastrointestinal function. While they have numerous ways of accomplishing those goals, some cases will still require referral for extensive monitoring, treatment, and possibly surgery.