Colic, Decision Making
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Once the veterinarian has carried out the examination, a decision as to whether the horse is a candidate for medical treatment or referral to a surgical facility for exploration, has to be made. Some cases will be difficult to diagnose and pose a problem to the decision to refer the horse. It is better for the veterinarian to refer the horse if there is any doubt as any further delay can make the difference between a sucessful and fatal outcome. The decision is based on a number of parameters listed below.
Parameters to Assist the Decision to Treat Medically or Surgically
- Pain
- Cardiovascular status
- Response to analgesia
- Response to medical therapy
- Rectal examination findings
- Quantity of garstric reflux
- Abdominal distension
- Abdominal auscultation
- Abdominocentesis results
- Ultrasonogaphic findings
These parameters will need to be reassessed over time to monitor for any change in the horse's condition and response to any therapy. A change in one or more of these parameters may be sufficient for referral to a surgical facility. The clinical signs as a result of pain and the response to analgesia are very important in assessing the need for surgery. Horse's with unrelenting pain that is not responsive to analgesia should be refered immediately. Rectal examinations are very useful in evaluating the colic patient as some surgical abnormalities of the gastrointestinal tract can be palpated.
| Parameter | For continuing medical treatment | Immediate surgery/euthanasia |
|---|---|---|
| Pain | Mild to moderate pain | Severe unrelenting pain |
| Response to analgesia | Good response to mild analgesics | No response or short-term response |
| Cardiovascular Status | Pulse < 60 bpm, Normal CRT and mucous membrane colour, PCV < 40, TPP lowered | Pulse > 60 bpm and rising, CRT prolonded, Mucous membranes injected or cyanotic despite fluid therapy, PCV > 40, TPP rising |
| Response to medical therapy | Positive response and improvement in cardiovascular status | No response and progressive cardiovascular collapse |
| Rectal Examination Findings | Negative rectal findings | Positive rectal findings indicative of acute abdominal disease |
| Abdominal Distension | No abdominal distension or resolving | Increasing distesion |
| Abdominal Auscultation | Continuous or revived intestinal motility | Progressive reduction in intestinal motiltiy to complete abscence of borborygmi |
| Quantity of Gastric Reflux | Less than 2 L or none at all | More than 2 L, continued reflux of alkaline, bile stained fluid |
| Ultrasonographic Findings | Normal examination | Abnormal examination |
| Abdominocentesis results | Negative results, straw-coloured fluid, TPP < 25 g/l, WBC < 10,000 WBC/ul | Positive results, serosanguinous fluid, TPP > 25 g/l, WBC's increased |
References
- Edwards B. (2009), Diagnosis and Pathophysiology of Intestinal Obstruction, in Equine Gastroenterology courtesy of the University of Liverpool, pp 9 - 10
- Meuller E, Moore J. N, (2008) Classification and Pathophysiology of Colic, Gastrointestinal Emergencies and Other Causes of Colic, in Equine Emergencies- Treatments and Procedures, 3rd Edition, Eds Orsini J. A, Divers T.J, Saunders Elsevier, pp 112