Objective—To determine prevalence and risk factors
for development of ileus of the large intestine after
surgery in horses, identified by reduced postoperative
fecal output (RPFO).
Animals—37 horses that developed RPFO after
undergoing general anesthesia for reasons unrelated
to the gastrointestinal tract.
Procedure—Fecal output was obtained from medical
records as number of defecations per 24-hour period
after surgery; RPFO was defined as ≤ 3 defecations
per 24-hour period after surgery. The reference population
included 48 horses that defecated ≥ 4 times
during the same period. Demographic, clinical, and
surgical variables were evaluated for their association
with development of RPFO by use of logistic regression
Results—Ten (12%) horses, all of which had RPFO,
developed signs of colic after surgery. Horses ≥ 5
years old that underwent orthopedic procedures of >
60 minutes’ duration and that did not receive
phenylbutazone after surgery were at significant risk
for developing RPFO.
Conclusions and Clinical Relevance—Results suggest
that after surgery unrelated to the gastrointestinal
tract in horses, there is an intermediate clinical
phase characterized by reduced fecal output preceding
overt signs of colic. Recognition of RPFO may
reduce morbidity and mortality of such horses. (J Am
Vet Med Assoc 2001;218:414–420)
Case Descriptions—16 horses treated daily with pyrantel tartrate (2.64 mg/kg [1.2 mg/lb], PO) as part of a prophylactic anthelmintic program.
Clinical Findings—Fecal worm egg counts (FWECs) were obtained on all 16 horses. Mean FWEC was 478 eggs/g (epg; range, 0 to 4,075 epg). Three of the 16 horses were responsible for 85% of the total fecal egg output for the herd on the day of sampling. Six horses had FWECs < 200 epg. Three horses that had arrived within 4 months of the sampling date had FWECs < 100 epg.
Treatment and Outcome—An FWEC reduction test was initiated the day after FWECs were obtained; all horses with FWECs > 100 epg (9 horses) were treated with pyrantel pamoate (6.6 mg/kg [3 mg/lb], PO), and 14 days later, the FWEC was repeated. During the 14-day period, all horses received pyrantel tartrate (2.64 mg/kg, PO) daily. Fecal worm egg count reduction was calculated for each horse. Mean FWEC reduction for the group was 28.5% (range, increase of 21% in FWECs 14 days after treatment to a decrease of 100% in FWEC 14 days after treatment).
Clinical Relevance—Farms should be monitored for cyathostomes resistant to pyrantel pamoate prior to use of pyrantel tartrate. Fecal worm egg counts should be monitored routinely in horses before and after treatment to ensure efficacy of cyathostome control measures.
Objective—To determine the effect of meloxicam and flunixin meglumine on recovery of ischemia-injured equine jejunum.
Procedures—Horses received butorphanol tartrate; were treated IV with saline (0.9% NaCl) solution (SS; 12 mL; n = 6), flunixin meglumine (1.1 mg/kg; 6), or meloxicam (0.6 mg/kg; 6) 1 hour before ischemia was induced for 2 hours in a portion of jejunum; and were allowed to recover for 18 hours. Flunixin and SS treatments were repeated after 12 hours; all 3 treatments were administered immediately prior to euthanasia. Selected clinical variables, postoperative pain scores, and meloxicam pharmacokinetic data were evaluated. After euthanasia, assessment of epithelial barrier function, histologic evaluation, and western blot analysis of ischemia-injured and control jejunal mucosa samples from the 3 groups were performed.
Results—Meloxicam- or flunixin-treated horses had improved postoperative pain scores and clinical variables, compared with SS-treated horses. Recovery of transepithelial barrier function in ischemia-injured jejunum was inhibited by flunixin but permitted similarly by meloxicam and SS treatments. Eighteen hours after cessation of ischemia, numbers of neutrophils in ischemia-injured tissue were higher in horses treated with meloxicam or flu-nixin than SS. Plasma meloxicam concentrations were similar to those reported previously, but clearance was slower. Changes in expression of proteins associated with inflammatory responses to ischemic injury and with different drug treatments occurred, suggesting cy-clooxygenase-independent effects.
Conclusions and Clinical Relevance—Although further assessment is needed, these data have suggested that IV administration of meloxicam may be a useful alternative to flunixin meglumine for postoperative treatment of horses with colic.