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Objective—

To assess the ability of clinicians to predict the site and type of lesion as well as outcome in horses with colic.

Design—

Prospective case study.

Sample population—

139 horses admitted for evaluation of signs of colic.

Procedure—

Six interns and residents examined horses with colic and predicted the segment of intestine that was affected, the type of lesion, and whether the horse would survive to discharge. Accuracy of prediction of site and type of lesion and survival prediction was compared between the first and second halves of the year, using X2 analysis and 95% confidence intervals on sensitivity and specificity. X2 Analysis was used to assess accuracy between predicted site and type of lesion and intraoperative or necropsy findings and to assess accuracy between predicted survival and actual outcome.

Results—

Significant association existed between predicted segment of affected intestine or type of lesion and intraoperative findings (P < 0.05). There was a significant association between predicted survival and outcome (P < 0.001). Accuracy of survival prediction improved significantly (P = 0.002) during the year.

Clinical Implications—

Clinicians can accurately predict horses with colic that will survive surgery on the basis of clinical impressions. The ability to predict those horses that will survive improves with training.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine an infusion rate of butorphanol tartrate in horses that would maintain therapeutic plasma drug concentrations while minimizing development of adverse behavioral and gastrointestinal tract effects.

Animals—10 healthy adult horses.

Procedure—Plasma butorphanol concentrations were determined by use of high-performance liquid chromatography following administration of butorphanol by single IV injection (0.1 to 0.13 mg/kg of body weight) or continuous IV infusion (loading dose, 17.8 µg/kg; infusion dosage, 23.7 µg/kg/h for 24 hours). Pharmacokinetic variables were calculated, and changes in physical examination data, gastrointestinal tract transit time, and behavior were determined over time.

Results—A single IV injection of butorphanol was associated with adverse behavioral and gastrointestinal tract effects including ataxia, decreased borborygmi, and decreased defecation. Elimination half-life of butorphanol was brief (44.37 minutes). Adverse gastrointestinal tract effects were less apparent during continuous 24-hour infusion of butorphanol at a dosage that resulted in a mean plasma concentration of 29 ng/ml, compared with effects after a single IV injection. No adverse behavioral effects were observed during or after continuous infusion.

Conclusions and Clinical Relevance—Continuous IV infusion of butorphanol for 24 hours maintained plasma butorphanol concentrations within a range associated with analgesia. Adverse behavioral and gastrointestinal tract effects were minimized during infusion, compared with a single injection of butorphanol. Continuous infusion of butorphanol may be a useful treatment to induce analgesia in horses. (Am J Vet Res 2001;62:183–189)

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in American Journal of Veterinary Research

Abstract

Objective

To determine whether quantification of myeloperoxidase (MPO) activity could be a useful laboratory technique to detect granulocyte infiltration in equine intestinal tissues.

Sample Population

Intestinal tissue (inflamed or healthy) collected from 16 age- and sex-matched Shetland Ponies.

Procedure

Intestinal tissue MPO activity was determined, and histologic assessment of adjacent specimens from healthy and inflamed intestine was done.

Results

Intestinal tissue MPO activity and histopathologic score increased with time after castor oil challenge and peaked at 16 hours in an equine diarrhea model in which individual ponies provided their own control tissues.

Conclusions

Intestinal tissue inflammation scores correlated positively with tissue MPO activity in adjacent specimens.

Clinical Relevance

Tissue MPO assay may be a useful laboratory tool to quantify intestinal mucosal inflammation in ponies. (Am J Vet Res 1999;60:807–813)

Free access
in American Journal of Veterinary Research

SUMMARY

Objectives

To determine the IV pharmacokinetics of cisapride and measure systemic absorption after rectal administration.

Animals

5 healthy adult mares (380 to 610 kg).

Procedure

Cisapride was administered, IV, at a dosage of 0.1 mg/kg of body weight. In the same horses, after a 1-week washout period, cisapride was administered rectally at a dosage of 1 mg/kg by mixing crushed tablets with propylene glycol and administering the mixture into the rectum. After each drug administration, a series of blood samples were collected. Plasma was obtained and analyzed by high-performance liquid chromatography to determine cisapride concentration profiles after each drug administration.

Results

After IV administration, peak plasma concentration was 221.4 ng/ml and harmonic mean half-life was 1.9 hours. Rectal absorption of cisapride was negligible. Cisapride was detected in plasma from only 3 of 5 horses for which mean systemic availability was 1.23%. Mean maximal plasma concentration after rectal administration of cisapride was 13.5 ng/ml.

Conclusion and Clinical Relevance

After IV administration of cisapride, plasma concentration is high for approximately 2 hours. Cisapride mixed with propylene glycol and administered rectally at a dosage of 1 mg/kg is poorly and incompletely absorbed. Thus, cisapride is not clinically useful for rectal administration in horses. (Am J Vet Res 1997;58:1427–1430)

Free access
in American Journal of Veterinary Research

Summary

Peritonitis was diagnosed in 67 horses between 1985 and 1990: 14 horses developed septic peritonitis after intestinal rupture, 25 horses developed peritonitis after abdominal surgery, and 28 horses had peritonitis not associated with intestinal rupture or abdominal surgery. Forty of 67 horses (59.7%) did not survive. Nonsurvivors had higher heart rates (P = 0.01), RBC count (P = 0.039), serum creatinine concentration (P = 0.036), pcv (P = 0.007), and anion gap (P = 0.005); lower venous blood pH (P = 0.002); and a greater number of bacterial species cultured from peritoneal fluid samples (P = 0.054), compared with those from survivors. Nonsurvivors were more likely to have signs of abdominal pain (P < 0.000), circulatory shock (P = 0.009), and bacteria in peritoneal fluid samples (P = 0.042). Physical examination and peritoneal fluid analysis were the most valuable diagnostic aids for intestinal rupture. Peritonitis after abdominal surgery resulted in high mortality (56%); peritonitis not associated with intestinal rupture or abdominal surgery had lower mortality (42.9%). Clinical and laboratory indices can be of value in determining the prognosis for horses with peritonitis.

Free access
in Journal of the American Veterinary Medical Association