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
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 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.
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.
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.
Objective—To determine whether there was an
association between a history of cribbing and epiploic
foramen entrapment (EFE) of the small intestine in
Animals—68 horses examined at the University of
Illinois or the University of Liverpool veterinary teaching
Procedure—For horses examined at the University of
Illinois that underwent surgery because of strangulating
small intestine lesions, information about cribbing
was obtained through telephone calls with owners.
For horses examined at the University of Liverpool
that underwent surgery for colic for any reason, information
about cribbing was obtained through a preoperative
Results—13 of 19 (68%) horses with EFE examined
at the University of Illinois had a history of cribbing,
compared with only 2 of 34 (6%) horses with other
strangulating small intestine lesions (odds ratio, 34.7;
95% confidence interval, 6.2 to 194.6). Similarly, 24 of
49 (49%) horses with EFE examined at the University
of Liverpool had a history of cribbing, compared with
72 of 687 (10.5%) horses with colic caused by other
lesions (odds ratio, 8.2; 95% confidence interval, 4.5
Conclusions and Clinical Relevance—Results suggest
that there may be an association between cribbing
and EFE in horses, with horses with a history of cribbing
more likely to have EFE than horses without such
a history. ( J Am Vet Med Assoc 2004;224:562–564)
Objective—To study the effects of phenylbutazone,
indomethacin, prostaglandin E2 (PGE2), glutamine,
and butyrate on restitution of oxidant-injured right dorsal
colon of horses in vitro.
Sample Population—Right dorsal colon from 9 adult
horses euthanatized for reasons other than gastrointestinal
Procedure—Mucosal segments from the right dorsal
colon were injured via exposure to HOCl and incubated
in Ussing chambers in solutions containing
phenylbutazone, indomethacin, indomethacin and
PGE2, glutamine, and butyrate. Transepithelial resistance
and mucosal permeability to mannitol were
measured, and all mucosal segments were examined
Results—The HOCl-injured mucosa had lower resistance
and higher permeability to mannitol, compared
with control tissue. Histologic changes were also evident.
Resistance of HOCl-injured mucosa recovered
partially during the incubation period, and glutamine
improved recovery. Phenylbutazone and
indomethacin increased resistance, but these
increases were not significant. Butyrate and PGE2
had no effects, compared with nontreated HOCl-injured
tissues. Mucosal permeability to mannitol was
lower in glutamine-treated tissue, compared with
nontreated tissue. Histologic changes reflected the
resistance and permeability changes.
Conclusions and Clinical Relevance—According to
our findings, phenylbutazone and indomethacin do
not seem to interfere with restitution of oxidant-injured
mucosa of equine colon in vitro, and glutamine
could facilitate mucosal restitution. (Am J Vet Res 2004;65:1589–1595)
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 induce ischemia and reperfusion injury in the large colon mucosa of horses in vivo and evaluate the recovery and effects of components of an organ transplant solution on mucosal recovery in vitro.
Animals—6 healthy horses.
Procedures—Horses were anesthetized, and ischemia was induced for 60 minutes in the pelvic flexure, which was followed by reperfusion for 240 minutes. Ischemic (n = 4 horses), reperfused (6), and adjacent control (6) colonic mucosae were isolated for in vitro testing and histologic examinations. Tissues were mounted in Ussing chambers with plain Krebs Ringer bicarbonate (KRB), KRB with N-acetylcysteine (NAC), or KRB with a modified organ transplant solution (MOTS). Transepithelial electrical resistance (TER) and mannitol flux were used to assess mucosal integrity. Data were analyzed by use of ANOVA and Kruskal-Wallis tests.
Results—The TER in reperfused tissues was similar to the TER in control tissues and greater than the TER in ischemic tissues, which was consistent with morphological evidence of recovery in reperfused tissues. Mannitol flux was greater in ischemic tissues than in reperfused tissues. The TER and mannitol flux were not significantly affected by incubation of mucosa with NAC or MOTS.
Conclusions and Clinical Relevance—Ischemia induced during the brief period allowed rapid mucosal repair and complete recovery of tissue barrier properties during reperfusion. Therefore, reperfusion injury was not observed for this method of ischemic damage in equine colonic mucosa.