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Objective—To evaluate survival rate and complications after jejunocecostomy in horses with colic and to compare outcomes after hand-sewn versus stapled side-to-side jejunocecostomy.
Design—Retrospective cohort study. Animals—32 horses.
Procedures—Information was retrieved from medical records and through telephone calls on horses that had a hand-sewn or stapled side-to-side jejunocecostomy for treatment of colic, which was performed by or under the supervision of the same surgeon. KaplanMeier life table analysis was used to compare survival times and rates between horses that underwent a hand-sewn or stapled side-to-side anastomosis.
Results—32 horses met inclusion criteria; 22 underwent a hand-sewn anastomosis, and 10 underwent a stapled anastomosis. Horses in the stapled group had a significantly greater prevalence of postoperative colic and combined postoperative colic and reflux than horses in the hand-sewn group. In the hand-sewn group, repeated celiotomy was performed within the same hospitalization period for 3 of 22 horses; in the stapled group, 4 of 10 horses had repeated celiotomies. Hospital discharge rates (ie, short-term survival rates) were similar between horses in the hand-sewn group (20/22 horses) and those in the stapled group (9/10 horses). Long-term survival rates were similar for both groups, ranging from 5 to 126 months. Conclusions and Clinical Relevance—Short- and long-term results justify use of jejunocecostomy in horses. Despite similar survival rates between groups, horses that underwent a stapled anastomosis had significantly greater prevalences of postoperative complications than horses that underwent a hand-sewn anastomosis, suggesting that horses were sensitive to minor differences in anastomosis techniques.
Objective—To test the hypothesis that strangulation of the small intestine by a lipoma or in the epiploic foramen is more common in older horses.
Procedure—Ages of horses with strangulation of the small intestine by a lipoma (n = 29) or in the epiploic foramen (17) were compared with ages of 79 horses with miscellaneous small intestinal lesions. Effects of increasing age on risk of the diseases of interest were examined by use of logistic regression and a 1-sided trend test for binomial proportions.
Results—Mean age of the horses with strangulation in the epiploic foramen (9.6 years) was the same as that for the horses with miscellaneous small intestinal lesions (7.7), but mean age of the horses with strangulation by a lipoma (19.2) was significantly greater than that for the other groups. The proportion of horses with lipoma increased significantly with increasing age, but the proportion with strangulation in the epiploic foramen did not.
Conclusions and Clinical Relevance—Results refute the current suggestion that increasing age predisposes horses for strangulation of the small intestine in the epiploic foramen but support the suggestion that the risk of strangulation of the small intestine by a lipoma increases with age. (J Am Vet Med Assoc 2001;219:87–89)
Objective—To determine the rate of development of septic arthritis after elective arthroscopy and evaluate associations between various factors and development of this complication in horses.
Design—Retrospective case series.
Animals—682 horses that underwent arthroscopic procedures at the University of Illinois Veterinary Teaching Hospital from 1994 to 2003.
Procedures—Information pertaining to signalment, joints treated, whether antimicrobials were administered, and development of postoperative septic arthritis was collected from medical records. Horses with a primary problem of septic arthritis or wounds involving joints were excluded. The following factors were evaluated to determine their roles in joint sepsis: breed, sex, joint, and preoperative and intra-articular administration of antimicrobials. Telephone interviews with clients were used to determine whether unreported septic arthritis had developed.
Results—8 of 932 (0.9%) joints in 7 of 682 (1.0%) horses that underwent arthroscopy developed postoperative septic arthritis. Follow-up information after discharge from the hospital was available for 461 of the 682 horses, and of those, 8 of 627 (1.3%) joints in 7 of 461 (1.5%) horses developed septic arthritis. Breed and joint treated were significant risk factors for development of postoperative septic arthritis, with draft breeds and tibiotarsal joints more likely than others to be affected. Sex, preoperatively administered antimicrobials, and intra-articularly administered antimicrobials were not associated with development of postoperative septic arthritis.
Conclusions and Clinical Relevance—Results can be used for comparison with data from other institutions and surgical facilities. Additional precautions should be undertaken when arthroscopic surgery involves draft breeds and tibiotarsal joints.
Objective—To determine effects of reactive oxygen metabolites (ROMs), with and without flunixin meglumine, on equine right ventral colon (RVC) in vitro.
Animals—18 healthy horses and ponies.
Procedures—In 3 groups of 6 animals each, short-circuit current and conductance were measured in RVC mucosa in Ussing chambers. The 3 groups received physiologic saline (0.9% NaCl) solution, IV, 10 minutes before euthanasia and tissue incubation in Krebs-Ringer-bicarbonate (KRB) solution; flunixin meglumine (1.1 mg/kg, IV) 10 minutes before euthanasia and tissue incubation in KRB solution; or physiologic saline solution, IV, 10 minutes before euthanasia and incubation in KRB solution with 2.7 × 10−5M flunixin meglumine. Incubation conditions included control (no addition) and ROM systems, including addition of 1mM xanthine and 80 mU of xanthine oxidase (to produce the superoxide radical), 1mM H2O2, and 1mM H2O2 and 0.5mM ferrous sulfate (to produce the hydroxyl radical).
Results—All ROMs that were added or generated significantly increased the short-circuit current except in tissues coincubated with flunixin meglumine, and they induced mild epithelial vacuolation and apoptosis, but did not disrupt the epithelium nor change conductance, lactate dehydrogenase release, or [3H]mannitol flux.
Conclusions and Clinical Relevance—Responses to ROMs could be attributed to increased chloride secretion and inhibited neutral NaCl absorption in equine RVC, possibly by stimulating prostaglandin production. The ROMs examined under conditions of this study could play a role in prostaglandin-mediated colonic secretion in horses with enterocolitis without causing direct mucosal injury.
To examine bicarbonate (HCO3 −) secretion ex vivo in the equine large colon to determine any differences between the right dorsal colon (RDC) and right ventral colon (RVC). The effect of phenylbutazone (PBZ) on HCO3 − secretion was examined in the RDC.
14 healthy horses.
In anesthetized horses (n = 10), segments of mucosa from RDC and RVC were harvested to measure HCO3 − secretion ex vivo with the pH Stat method. The effect of PBZ on HCO3 − secretion in the RDC was studied in 4 additional horses.
Three distinct mechanisms of HCO3 − secretion previously described in a murine model were confirmed in the equine colon. The RDC had a greater capacity for electrogenic, Cl−-independent HCO3 − secretion than the RVC (P = 0.04). In the RDC, all HCO3 − secretion was decreased by PBZ (P < 0.02) but was not studied in the RVC because of low baseline secretion.
Secretion of HCO3 − by the RDC could play a pivotal role in equine colon physiology, because intense microbial fermentation in this site could require HCO3 − secretion to buffer short-chain fatty acids. Inhibition of this secretion by PBZ could interfere with mucosal buffering and predispose to changes associated with right dorsal colitis.
Case Description—A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye.
Clinical Findings—Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulcer-ation of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic examination revealed right-sided otitis media. Temporohyoid osteoarthropathy in the right guttural pouch and mycosis in the left guttural pouch were diagnosed.
Treatment and Outcome—Ceratohyoidectomy of the right stylohyoid bone was performed, and the left internal carotid artery was occluded via placement of stainless steel spring embolization coils. The mare regained the ability to eat without difficulty and improved clinically for approximately 4 weeks. However, the mare returned to the medical center 53 days after surgery with left-sided Horner syndrome, atrophy of the right side of the tongue, and a 3-week history of dysphagia and weight loss. Endoscopic evaluation revealed progression of mycotic growth in the left guttural pouch. The mare was euthanatized.
Clinical Relevance—Although the mycotic lesion in the left guttural pouch was an incidental finding at the time of initial examination, the lesion progressed to cause dysphagia and Horner syndrome after occlusion of the left internal carotid artery, a treatment that is typically associated with resolution of guttural pouch mycosis. Arterial occlusion is not necessarily a reliable method of resolving guttural pouch mycosis.
Objectives—To compare abomasal emptying rates in calves after suckling milk replacer or 3 common orally administered electrolyte solution components.
Animals—5 male calves < 35 days of age.
Procedures—Calves with a cannula fitted in the abomasal body were fed 2 L of milk replacer with or without parenteral administration of atropine (0.01 mg/kg, IV, then 0.02 mg/ kg, SC, q 30 min) or isotonic (150mM) solutions of sodium acetate, NaHCO3, or NaCl in a randomized crossover design. Abomasal emptying rates were determined via scintigraphy, acetaminophen absorption, ultrasonography, and change in abomasal luminal pH.
Results—Scintigraphic half-emptying time, time of maximal plasma acetaminophen concentration, ultrasonographic half-emptying time, and pH return time indicated similar abomasal emptying rates following suckling of isotonic sodium acetate, NaHCO3, and NaCl solutions, whereas the emptying rate of milk replacer was significantly slower. Mean maximal abomasal luminal pH was highest following suckling of NaHCO3 (pHmax = 7.85) and lowest following suckling of NaCl (pHmax = 4.52); sodium acetate (pHmax = 6.59) and milk replacer (pHmax = 5.84) yielded intermediate pH values.
Conclusions and Clinical Relevance—Isotonic solutions of sodium acetate, NaHCO3, and NaCl were rapidly emptied from the abomasum but varied markedly in their ability to alkalinize the abomasum. Sodium bicarbonate–containing orally administered electrolyte solution might increase the frequency of infection or severity of clinical disease in diarrheic calves treated for dehydration by causing prolonged abomasal alkalinization.
Objectives—To establish reference values for the range of the number of eosinophils found in equine gastrointestinal mucosa and to describe the distribution of this cell within the equine gastrointestinal mucosa.
Sample Population—Gastrointestinal mucosal specimens from 14 adult horses euthanatized for reasons other than gastrointestinal disease.
Procedures—Gastrointestinal mucosal specimens were collected and grouped according to their anatomic regions. For histologic examination slides were stained with Luna's eosinophil stain to determine eosinophil accumulation and distribution. The mucosa was divided into 5 sections for each anatomic location, and the percentage of eosinophils in each of the 5 sections relative to the total eosinophil count in all sections was determined. Additionally, the number of eosinophils per square millimeter of mucosa was calculated as a measure of the degree of eosinophil accumulation.
Results—Lowest numbers of eosinophils were found in the stomach, and numbers increased from there to the cecum, then decreased from the ascending colon (right ventral colon, left ventral colon, pelvic flexure, left dorsal colon, and right dorsal colon) to small colon. In all gastrointestinal sections, most eosinophils were located near the muscularis mucosae and were rarely found near or on the luminal surface of the mucosa.
Conclusions and Clinical Relevance—The distribution of eosinophils in the gastrointestinal tract of horses followed a pattern within the mucosa and between different sections of the gastrointestinal tract. The derived reference values and distribution data could be used to detect changes in eosinophil response in the equine gastrointestinal mucosa caused by diseases states.
Objective—To identify expression and localization of cyclooxygenase (COX)-1 and COX-2 in healthy and ischemic-injured left dorsal colon of horses.
Sample Population—Left dorsal colon tissue samples from 40 horses.
Procedures—Tissue samples that were used in several related studies on ischemia and reperfusion were evaluated. Samples were collected during anesthesia, before induction of ischemia, and following 1 hour of ischemia, 1 hour of ischemia and 30 minutes of reperfusion, 2 hours of ischemia, 2 hours of ischemia and 30 minutes of reperfusion, and 2 hours of ischemia and 18 hours of reperfusion. Histomorphometric analyses were performed to characterize morphological injury. Immunohistochemical analyses were performed to characterize expression and localization of COX-1 and COX-2.
Results—COX-1 and COX-2 were expressed in control tissues before ischemia was induced, predominantly in cells in the lamina propria. Ischemic injury significantly increased expression of COX-2 in epithelial cells on the colonic surface and in crypts. A similar significant increase of COX-1 expression was seen in the epithelial cells.
Conclusions and Clinical Relevance—On the basis of information on the role of COX-2, upregulation of COX-2 in surface epithelium and crypt cells following ischemic injury in equine colon may represent an early step in the repair process.
Objective—To examine the effects of flunixin meglumine (FM) on recovery of colonic mucosa from experimentally induced ischemia in horses.
Animals—14 research horses.
Procedures—Ischemia was induced in the colons of anesthetized horses for 2 hours. Afterward, horses received saline (0.9% NaCl) solution (12 mL, IV, q 12 h; n = 7) or FM (1.1 mg/kg, IV, q 12 h; 7) and were allowed to recover for 18 hours after termination of the ischemic event. Postoperative pain scores were recorded every 4 hours throughout the recovery period. At the end of the recovery period, horses were anesthetized, and ischemic and nonischemic segments of colonic mucosa were harvested for histologic evaluation, western blot analysis, and in vitro assessment of transepithelial electric resistance (TER) and transmucosal flux of tritium-labeled (3H-) mannitol. Horses were then euthanatized.
Results—Flunixin meglumine significantly lowered pain scores at the first postoperative recording. There were no significant differences between treatment with saline solution and FM in any of the measurements for TER, 3H-mannitol flux, histomorphometric variables, neutrophil infiltration (detected via calprotectin immunostaining), and expressions of cyclooxygenase-1 and -2. After both treatments, TER declined significantly in nonischemic tissues in vitro, whereas it increased significantly in ischemic-injured tissues.
Conclusions and Clinical Relevance—Flunixin meglumine did not affect recovery of equine colonic mucosa from ischemic injury, and continued use in horses with colonic ischemia is therefore justified.