Clinical evaluation of the equine colic patient

Determination of a gravity and shock score for prognosis in equine surgical colic

A retrospective study evaluated 200 surgical colic cases. A gravity score (GS) based on four clinical parameters estimating intestinal obstruction (rectal palpation, borborygmi, abdominal distension, pain) and classified into three categories was established and tested to determine if it could evaluate prognosis. A shock score (SS) based on six parameters was also attributed to each case. The overall survival rate was 54%. The statistical analysis showed a significant (P < 0.01) difference in the survival rate in the different categories of the GS, as well as in the categories of the SS. A multivariate logistic regression model showed that horses with GS 3 are 10.6 times more likely to die than those with GS 1. A model combining the two scores showed an odds ratio of 7.1 for GS 3 versus GS 1, and for SS 3 versus SS 1, the odds ratio was 7.2.

Surgical reduction of ileal impactions in the horse: 28 cases

OBJECTIVE

To evaluate the seasonal influence, signalment, type of hay consumed, clinical examination findings, and outcome after surgery for horses with ileal impaction.

STUDY DESIGN

A retrospective study.

RESULTS

Between 1988 and 1993, 28 horses had surgical correction of ileal impaction. There was a significantly higher rate of ileal impaction during the Fall (September-November, P = .0041 ). Mean duration of clinical signs of abdominal pain before referral was 15 hours. Transrectal palpation was used to localize the impaction in 11 horses. The ileal impaction was reduced by extraluminal massage aided by admixing of intestinal fluid oral to the impaction or injection of fluids intraluminally and then movement of the ingesta into the cecum alone in 24 horses. A total of 26 horses recovered from surgery; 24 horses were discharged from the hospital and eventually returned to previous use. Two horses had fatal postoperative complications: jejunocecostomy dehiscence and development of extensive small intestine adhesions after manual reduction of the impaction. One horse initially treated by manual reduction required jejunocecostomy twice for management of recurrent ileal impaction. Follow-up information was obtained for 21 horses, of which 20 were alive 1 year or longer after surgery. A total of 27 of 28 horses were fed Coastal Bermudagrass hay as the primary type of hay consumed. A total of 9 horses continued to be fed Coastal Bermudagrass hay as the only roughage source, whereas 6 horses were fed Coastal Bermudagrass with at least 50% other hay, and in 6 horses, Coastal Bermudagrass hay was entirely eliminated from the diet.

CONCLUSION AND CLINICAL RELEVANCE

Ileal impactions can be successfully reduced by celiotomy and extraluminal massage and injection techniques to soften the ingesta for passage into the cecum without enterotomy or bypass techniques in most horses. Changes in weather and feeding practices in the Fall may account for an increased risk of ileal impaction in horses in the southeastern United States at that time of year.

Alternative diagnoses in the colic patient

Despite clinical signs compatible with obstruction or ischemia of the gastrointestinal tract, the clinician occasionally is unable to identify a gastrointestinal cause for colic. In this article, disorders not originating from obstruction or ischemia of the gastrointestinal tract but causing real or apparent abdominal pain are presented as alternative causes of colic. In addition, colic of gastrointestinal origin may be the primary inciting factor or a secondary complication of an alternative disorder, causing colic-like signs. Recognition of alternative diagnoses relies on a thorough and consistent approach to the clinical assessment of the equine colic patient and helps to ensure appropriate patient management.

Examination of the horse with colic

The purpose of this detailed description of the clinical examination of the colic patient is to arrive at a specific diagnosis. However, this is hardly ever possible, but the practitioner should be in the position to establish the suspicion of an intestinal obstruction or to rule out its presence during the course of the development. Single clinical findings should not be interpreted in isolation but in relation to one another, so that a false diagnosis is not made. All clinical findings should be documented, so that when repeated examinations are carried out, findings can be compared with one another. This is also important in the evaluation of the cause of the condition; also, it will be easier to discern the results of therapy.

Survival rates and post-operative complications after equine colic surgery

A retrospective analysis of 74 cases that underwent surgery for colic was undertaken to determine short and long term survival rates and the incidence of post-operative complications. In 28 cases colic was related to small intestinal lesions and in 46 cases to large intestinal lesions. Pre-operative packed cell volume and heart rate were found to be inversely related to short-term survival. Twenty-five horses (34%) recovered from surgery and were discharged. Of 18 of these cases with available histories, 6 subsequently had one or more episodes of colic since surgery of which 5 eventually died or were euthanased due to further colic; the remaining 12 have remained free from recurrence of colic for longer than 6 months.

Assessment of the necessity for surgical intervention in cases of equine colic: a retrospective study

The present study retrospectively examined clinical and clinicopathological findings in horses with colic to determine which variables distinguished between medically treatable cases and cases which required surgical intervention. Heart rate, haematocrit, haemoglobin concentration, blood erythrocyte count, frequency of borborygmi and degree of mental depression showed the greatest differences (P less than 0.001) between medical and surgical groups. However, some variables which primarily evaluated cardiovascular function, ie, blood pressure, oral mucosal capillary refill time and blood lactate concentration, were not significantly different between medical and surgical groups. When several of the following findings are observed together surgery is suggested: moderate to marked colic signs; tacky to dry oral mucosa which is discoloured (especially when brick-red or blue); decreased to absent borborygmi, probably associated with absence of rectal faeces; nasograstric intubation producing refluent fluid; leucocytosis with a left-shift; and tachypnoea, tachycardia, elevated haematocrit, hyperglycaemia and uraemia.