Abdominal Ultrasonography in the Equine Patient with Acute Signs of Colic

IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

Abdominal Ultrasonography in the Equine Patient With Acute Signs of Colic

Andreas Klohnen, DVM, Diplomate ACVS

1. Introduction of a horse with signs of abdominal pain, the baseline Abdominal pain in horses is one of the most common pain level should be considered. An abdominal ul- presenting clinical signs and a major cause of mor- trasound examination should not be performed if a tality in horses. Rapid and effective evaluation of horse has fractious behavior or is showing signs of horses with signs of colic is necessary for prompt uncontrollable abdominal pain despite sedation. surgical intervention, thereby allowing for more suc- The abdominal wall is saturated with isopropyl cessful outcomes. However, determining the ac- alcohol using a spray bottle to dampen the hair and tual cause of colic in horses is a diagnostic challenge, create adequate contact with the transducer to and the decision for selecting abdominal surgery in achieve adequate image quality. Ultrasonographic horses with colic is not always straightforward. coupling gel can then be applied liberally to the Analgesic administration or stoic horses may delay ultrasound transducer to further enhance the image necessary abdominal surgery, resulting in a de- quality. A 3.5-MHz convex linear transducer with creased prognosis for survival. a maximal depth range of at least 25 cm is used for The decision between medical management and sur- ultrasonographic examination of the equine abdo- gical intervention is largely made on the basis of phys- men. To evaluate the deeper areas of the equine ical examination, abdominocentesis, abdominal abdomen, the focal zones should be positioned in the palpation per rectum and, most importantly, persis- far ﬁeld to enhance visualization of deeper struc- tent signs of abdominal pain despite medical treat- tures. In most ambulatory settings, a practitioner ment. More recently, abdominal radiography and may not have a 3.5-MHz probe available. A 5-MHZ abdominal ultrasonography have become more useful linear rectal probe may be used instead but will give in evaluating horses with abdominal pain. Several the examiner a much smaller ultrasonographic win- recent studies have shown that abdominal ultrasonog- dow of the abdomen. The 5-MHz probe does not raphy in the colic patient can be a very useful diagnos- provide the same level of penetration as a 3.5-MHz tic tool. convex linear transducer, but it is adequate to evaluate portions of the equine adult abdomen for signs Technique of abdominal pain. Abdominal ultrasonography is a very safe and non- A systematic approach to each ultrasound exami- invasive diagnostic test. After initial examination nation in a horse for signs of colic is recommended.

NOTES

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Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 8 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

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Fig. 1. Large colon wall.

The abdomen is divided into three regions (right paralumbar fossa [PLF] region, ventral region/inguinal region, and left paralumbar fossa). Each region can be further subdivided into right PLF 1, 2, and 3; ventral (V) 1, 2, and 3; and left PLF 1, 2, and 3. The examination should start in the right paralumbar fossa and continue to the ventral/inguinal region and then the left paralumbar fossa region after the horse is C turned around or the machine moved to the other side O of the horse. The right and left intercostal regions L should also be evaluated for possible intestinal abnor- O malities. The margins of these regions are meant to R serve as a guideline for a systemic ultrasound examination. In most equine cases with colic, an individual Fig. 2. A, Distended loop of small intestine. B, Several distended region does not correspond with a speciﬁc diagnosis for loops of small intestines. the signs of colic.

Abdominal Ultrasound of the Normal Horse the width of the measuring cursors (Ͻ3mm). Itis In clinically normal horses without signs of abdom- very rare to visualize distended loops of small intes- inal pain, the large intestine can be distinguished tine in a clinically normal horse. from the small intestine by size and appearance. The nephro-splenic space is imaged in the left PLF The large colon can be visualized in all three regions 1 region, where the left kidney and caudal edge of and appears as a bright hyperechoic line correlating the spleen are consistently identified (Fig. 3). The F3 with the ventral colon sacculations or the wall of the stomach wall should be visualized in the left inter- F1 dorsal colon (Fig. 1). Because of the size of the costal spaces, but the stomach should not be dis- large colon and the presence of gas and feed within tended with fluid. the colon, the deep border is often not visualized and Examination of the right PLF 1 region and the the colon cannot be imaged as a complete loop. rightmost caudal intercostal areas should demon- In a normal horse, individual layers of the colon are strate the right kidney and the duodenum. In a not typically visible. clinically normal horse, there should not be any Transverse sections of the small intestine are im- significant distention or increased wall thickness in aged as complete loops, and usually more than 1 loop the duodenum. F2 can be viewed (Fig. 2, A and B). In a normal horse, In a clinically normal horse, the ventral region the small intestine can be imaged as circular densi- (V1, just caudal to the sternum) may demonstrate ties that show continuous movement. The small the presence of abdominal fluid. intestine is often visible along the ventral axial sur- face of the spleen from the left side and in the Abdominal Ultrasound of the Horse With Signs of inguinal regions. Small intestine wall thickness in Abdominal Pain clinically normal horses is difficult to measure when Abdominal ultrasound in the horse with signs of scanning at maximal depth because it is less than abdominal pain has been most helpful for the detec-

12 2012 ր Vol. 58 ր AAEP PROCEEDINGS

Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

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Fig. 3. Normal anatomy of the left paralumbar fossa.

Fig. 4. Sand accumulation in the colon. tion and diagnosis of strangulating and nonstrangu- lation lesions of the small intestine. Each region and subregion of the abdomen is examined ultra- sonographically, and the detection of either large small intestine that are secondary to the primary intestine and/or small intestine is recorded. Im- problem (colonic enterolith). The gold standard for ages of the small intestine (jejunum) and duodenum the detection of an enterolith in the large colon is are measured for diameter and wall thickness. abdominal radiographs. In the author’s opinion, The detection of intestinal motility is recorded. colonic enteroliths are not detectable with abdomi- Small intestinal motility is defined as contraction nal ultrasound. and subsequent distention of the small intestinal walls with a change in luminal diameter. In some Horses With Peritonitis, Ruptured Intestines, Abdominal horses with small intestinal lesions, there is com- Fluid Analysis plete absence of small intestinal motility. Abdominal ultrasonography of a horse with perito- Additionally, the nephro-splenic space (left PLF l nitis will usually show several slightly distended and left PLF 2) is evaluated for either a left dorsal loops of small intestine with a very thickened small colon displacement or a nephro-splenic entrapment of the large colon. The left intercostal spaces (ribs 10 to 13) are also evaluated for possible distention of the stomach with fluid (gastric reflux).

Horses With Sand Accumulation in the Colon (Sand Colic) Abdominal ultrasonography of a horse with sand colic usually will not show any distended, amotile loops of small intestine. Some horses with sand colic may show signs of minimally distended small intestine loops filled with fluid or ingesta, which are subsequent to the primary sand colic problem. The gold standard for the detection of sand in the F4 large colon is abdominal radiography (Fig. 4). Ab- dominal ultrasound of a horse with sand accumulation in the colon will reveal the large colon wall in the ventral region to appear “brighter” and more hyperechoic. This ultrasonographic finding is related to the ultrasonographic reflection of the sand F5 particles (Fig. 5). C O Horses With Large Colon Enteroliths and/or Small Colon L Enteroliths O Abdominal ultrasonography of a horse with a large R colon enterolith or small colon enterolith usually will not show any distended or amotile loops of small Fig. 5. Ultrasonographic view of the large colon wall in the intestine but may show minimally distended loops of ventral region showing evidence of sand in the colon.

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Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

C O L O R

Fig. 6. Slightly distended loops of small intestine with very thickened intestinal wall, indicative of peritonitis.

F6 intestinal wall (Fig. 6). The small intestinal motility may vary. The thickened loops of small intestine are usually best visualized in the ventral or inguinal re- C gions. The ventral 1 region (close to the sternum) O may reveal an increased amount of abdominal fluid. L The abdominal fluid may be “gray” or hazy in appear- O ance. In some horses, it is possible to visualize the R actual cause of the peritonitis such as an intestinal or F7 mesenteric abscess (Fig. 7, A and B). Fig. 7. A, Abdominal ultrasound of a horse with an intra-abdom- A horse with intestinal rupture will have a vary- inal abscess. B, Abdominal ultrasound of a horse with a large ing amount of increased abdominal fluid and vary- intra-abdominal abscess. ing stages of distended and edematous loops of small F8 intestine (Fig. 8). The appearance may vary, de- pending on the time interval from rupture to abdom- Horses With Anterior Enteritis inal ultrasound examination. Abdominal ultrasonography can be helpful in lo- Abdominal ultrasonography of a horse with anterior cating an area in the ventral abdominal region with enteritis usually will reveal a fluid-filled stomach an increased amount of abdominal fluid, in order to perform abdominocentesis (Fig. 8). Normal abdominal fluid should appear anechoic or “black” on the ultrasound screen.

Gastric Distention With Fluid (Reflux) The equine stomach is located between ribs 10 and 13 on the left side of the abdomen. It is the author’s opinion that a normal equine stomach will not show any evidence of gastric fluid. The outer wall of the stomach can be identified and shows a similar appearance as the wall of the large colon. Once the stomach is filled with fluid or reflux, the lesser and C greater curvature will become visible during an ul- O F9 trasonographic examination (Fig. 9). The amount L of gastric distention seen on ultrasound will depend O on the quantity of gastric reflux. A horse with a R distended, fluid-filled stomach should have a stomach tube placed to further evaluate the horse for the Fig. 8. Abdominal ultrasound view of the ventral region indicat- presence of gastric reflux. ing an increased amount of abdominal fluid.

14 2012 ր Vol. 58 ր AAEP PROCEEDINGS

Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

C O L O R

Fig. 9. Distended stomach with gastric reﬂux.

C O caused by gastric reflux on the left side of the abdo- L men. The duodenum is usually also distended and O may appear edematous and possibly amotile. The R duodenum is visible cranial to the right paralumbar fossa 1 region in the right caudal intercostal spaces. Fig. 10. Multiple distended loops of small intestine with no Further examination of the right paralumbar fossa evidence of motility indicating a strangulation obstruction. and ventral region will reveal several slightly distended but very edematous loops of small intestine with decreased motility. A horse with anterior enteritis may have an increased amount of abdominal Horses With Right Dorsal Colon Displacement fluid in the cranioventral abdominal region. Horses with a right dorsal colon displacement will not have a distinct ultrasonographic appearance. Horses With Strangulating Obstruction of the Small There may be many slightly distended loops of small Intestine intestine that are filled with ingesta. The small Abdominal ultrasonography of a horse with a stran- intestinal changes seen are usually secondary to the gulating obstruction of the small intestine will show primary large intestinal problem. The colonic wall several distended loops of small intestine adjacent to usually is not edematous, but the colonic vessels each other (three to eight loops of small intestine per may be very distended in the right paralumbar fossa field) with either slow small intestinal motility or no region, and the vessel walls may be edematous. F10 small intestinal motility (Fig. 10). Some of the distended loops of small intestine can be thickened or Horses With Nephro-Splenic Entrapment of the Large edematous. Most of the distended loops of small Colon and Left Dorsal Colon Displacement intestine can be visualized in the right lower Abdominal ultrasonography in horses with a “true” paralumbar fossa region (right PLF 3), ventral re- nephro-splenic entrapment of the large colon, de- gions, or inguinal regions. The cranial abdomen fined as colon located in the nephro-splenic space may reveal an increased amount of free abdominal between the dorsal edge of the spleen and the left fluid, and the stomach may be filled with gastric kidney, the left kidney cannot be visualized, the fluid due to reflux. typical appearance of the rounded, caudodorsal border of the spleen is lost, and a colonic gas shadow is Horses With Large Colon Torsion seen next to the dorsal edge of the spleen (Fig. 11). F11 In most horses with a large colon torsion or volvulus, Horses may have varying amounts of gastric fluid an abdominal ultrasound cannot be performed be- and may have signs of slightly distended loops of cause many horses with a colon torsion show signs of small intestine with reduced small intestinal motil- uncontrollable abdominal pain despite sedation. ity; however, these small intestinal changes are sec- If an abdominal ultrasound can be performed, the ondary to the primary large intestinal problem. large colon wall visualized in the right paralumbar In horses with a left dorsal colon displacement, fossa or the ventral region will be very edematous defined as colon located dorsal to the spleen and not (Ͼ8 mm thick). The colonic vessels seen in the in the nephro-splenic space, the left kidney may right paralumbar fossa region can be dilated and either be fully visualized or only partially visualized. edematous. The typical appearance of the rounded, caudodorsal

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Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN

Fig. 11. Abdominal ultrasounds of a horse with a nephro-splenic entrapment of the large colon.

border of the spleen is either completely or partially nal radiography, and ultrasonographic examination lost, and a colonic gas shadow is seen next to the of the abdomen. Horses were excluded from the dorsal edge of the spleen. The entire dorsal edge of study if they were unable to be examined ultrasono- the spleen cannot be visualized from cranial to cau- graphically because of fractious behavior or uncon- F12 dal, and instead colon wall will be seen (Fig. 12). trollable abdominal pain. Usually these horses respond to treatment with in- During the study period, 3092 horses with signs of travenous fluid therapy and intravenous phenyleph- colic were evaluated with abdominal ultrasonogra- rine therapy. Upon resolution of the displacement, phy. Of these horses, 1526 were treated medically the dorsal edge of the spleen will become visible next (49.4%), 1477 underwent exploratory celiotomy to the left kidney on consecutive abdominal ultra- (47.8%), and 89 horses were euthanatized (2.9%). sound exams. Medical Cases Validation of Abdominal Ultrasonography for Horses With Of the medically treated horses, 436 of 1526 (28.6%) Abdominal Pain had no small intestine visualized during the abdom- During a 7.5-year study period, the following proce- inal ultrasound examination, and 1080 (70.8%) had dures were performed on horses admitted to Chino a few normal-appearing loops of small intestine vi- Valley Equine Hospital for signs of colic: physical sualized. Several very small loops of small intes- examination, complete blood count (CBC), abdomi- tine were detected next to the ventral edge of the nal fluid analysis (total protein, cytologic exami- spleen and/or in the caudal inguinal region. Forty- nation, white blood cell count), placement of a one (3.8%) appeared to have a gas shadow next to nasogastric tube to obtain gastric reflux, abdominal the dorsal edge of the spleen and were treated med- palpation per rectum by a senior clinician, abdomi- ically for a possible left dorsal colon displacement. Ten (0.6%) horses appeared to have increased num- bers of distended small intestine loops but showed good motility.

Euthanasia With Postmortem Examination Group Forty-six of 89 euthanatized horses (51.7%) did not appear to have any distended loops of small intestine on abdominal ultrasound. Necropsy examination confirmed that the cause of the colic was unrelated to the small intestine. In 43 euthanatized horses (48.3%), abdominal ultrasound revealed distended loops of small intestine. In 33 of these horses, an ultrasonographic diagnosis of a strangulation obstruction was made and confirmed during necropsy examination. The remain- C ing 10 horses appeared to have small, very O L edematous loops of small intestine secondary to O peritonitis from a ruptured viscus. R Surgical Small Intestine Group Fig. 12. Ultrasound of the left flank region and left paralumbar A strangulation obstruction was diagnosed in 255 fossa region demonstrating large colon wall instead of the spleen. horses with the help of abdominal ultrasound and

16 2012 ր Vol. 58 ր AAEP PROCEEDINGS

Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407 IN-DEPTH: ULTRASOUND OF THE THORAX AND ABDOMEN confirmed during exploratory celiotomy. All 255 Abdominal Ultrasound to Detect and Monitor cases required a small intestinal resection and anas- Postoperative Ileus tomosis. A diagnosis of nonstrangulating small in- Postoperative ileus is an important cause of morbid- testinal obstruction was made in 141 horses. In ity and mortality in the postsurgical period for 139 of these horses, the primary cause of colic was horses with colic. The diagnosis has classically confirmed to be related to the small intestine on been made on the basis of postoperative reflux ob- exploratory celiotomy and required a small intesti- tained through nasogastric intubation and postoper- nal resection. Two horses of the 141 horses were ative signs of abdominal pain in conjunction with found to have a primary large colon problem with a reflux. According to the veterinary literature, post- secondary small intestinal component. operative ileus has mainly been defined by the vol- In 49 horses, the abdominal ultrasound revealed ume of reflux that is recovered from a horse during several small but very edematous loops of small a 24-hour period. Abdominal ultrasonography is a intestine. In every case, an exploratory celiotomy proven diagnostic modality in the preoperative diag- confirmed the preoperative diagnosis of abnormal nosis of small intestinal lesions and is potentially a small intestine. useful diagnostic imaging technique to assess distention, contractility, wall edema, and motility of small intestine after surgery. In a study of 830 Surgical Large Intestine Group postoperative cases at our clinic, postoperative ileus In 555 horses, a preoperative abdominal ultrasound was defined as the presence of multiple (n Ͼ 3) revealed no evidence of small intestinal abnormali- distended loops of small intestine with decreased ties. In 412 horses, preoperative ultrasound re- intestinal contractility and motility. Horses were vealed mainly findings related to the large intestine, evaluated every 24 hours after surgery until there with only a few loops of small intestine that showed was no further evidence of small intestinal disten- minimal small intestinal distention. In all 412 tion. After the diagnosis of ileus was established, cases, exploratory celiotomy confirmed the ultra- horses were treated with a slow IV lidocaine bolus sonographic findings of a large intestinal lesion. (1.3 mg/kg over 15 minutes) followed by an infusion In 14 cases, a preoperative ultrasonographic diagno- of 0.05 mg/kg per minute of lidocaine in saline until sis of a left dorsal colon displacement was made. complete ultrasonographic resolution of postopera- None of these horses responded to medical therapy, tive ileus was achieved. Of the 213 horses that and an exploratory celiotomy confirmed left dorsal showed ultrasonographic evidence of postoperative colon displacement. In 51 cases, a preoperative intestinal ileus, 130 (61%) had no evidence of naso- presumptive diagnosis of nephro-splenic entrap- gastric reflux, whereas 83 horses (39%) had reflux. ment of the large colon was made on the basis of Sixty-seven of these horses (32%) were diagnosed abdominal ultrasound. In all 51 cases, the preop- with a large intestinal lesion, representing 19% of horses with a primary diagnosis of large intestinal erative findings were confirmed. disease during the study period. Sixty-eight per- cent (146 horses) were diagnosed with a primary 2. Discussion small intestinal lesion, which represented 37% of Previous studies have confirmed the utility of ab- horses with a primary diagnosis of small intestine dominal ultrasonography for the evaluation of disease. horses with signs of colic. In one study, Klohnen et We have found that abdominal ultrasound is a al1 evaluated the use of diagnostic ultrasonography reliable method for the diagnosis and monitoring of in horses with signs of acute abdominal pain. In postoperative intestinal ileus and may provide a this study, abdominal ultrasonography showed more useful indicator than volume of gastric reflux. 100% sensitivity and specificity to diagnose strangu- Reference lation obstructions of the small intestine. 1. Klohnen A, Vachon AM, Fischer AT Jr. Use of diagnostic In the current study described in this report, ab- ultrasonography in horses with signs of acute abdominal dominal ultrasonography was very helpful to distin- pain. J Am Vet Med Assoc 1996;209:1597–1601. guish between medical problems and surgical Suggested Reading disorders of the large colon and small intestine. 1. Henry Barton M. Understanding abdominal ultrasonogra- In horses with medical colic or in horses with large phy in horses: which way is up? Compend Contin Educ Vet colon disorders, either no small intestinal distention 2011;33:E1–E8. or only multiple loops of slightly distended small 2. Grenager NS, Durham MG. Ultrasonographic evidence of intestinal loops were seen. Overall, this large case colonic mesenteric vessels as an indicator of right dorsal displacement of the large colon in 13 horses. Equine Vet J series validates the utility of abdominal ultrasonog- 2011;43(Suppl 39):153–155. raphy in the evaluation of equine colic patients. 3. Beccati F, Pepe M, Gialletti R, et al. Is there a statistical Most importantly, abdominal ultrasonography correlation between ultrasonographic findings and definitive should be recognized as extremely valuable to deter- diagnosis in horses with acute abdominal pain? Equine Vet J 2011;43(Suppl 39):98–105. mine strangulating obstructions of the small 4. No´gra´diN,To´th B, Macgillivray KC. Peritonitis in horses: intestine. 55 cases (2004–2007). Acta Vet Hung 2011;59:181–193.

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5. Conwell RC, Hillyer MH, Mair TS et al. Haemoperitoneum 15. Mogg TD, Rutherford DJ. Intra-abdominal abscess and in horses: a retrospective review of 54 cases. Vet Rec 2010; peritonitis in an Appaloosa gelding. Vet Clin North Am 167:514–518. Equine Pract 2006;22:e17–e25. 6. Trachsel DS, Grest P, Nitzl D, et al. Diagnostic workup of 16. Valdes-Martinez A, Waguespack RW. What is your diagno- chronic inflammatory bowel disease in the horse. Schweiz sis? Cecocolic intussusception. J Am Vet Med Assoc 2006; Arch Tierheilkd 2010;152:418–424. 228:847–848. 7. Busoni V, De Busscher V, Lopez D, et al. Evaluation of a 17. Abutarbush SM. Use of ultrasonography to diagnose large protocol for fast localized abdominal sonography of horses colon volvulus in horses. J Am Vet Med Assoc 2006;228:409– (FLASH) admitted for colic. Vet J 2011;188:77–82. 413. 8. Pusterla N, Wattanaphansak S, Mapes S, et al. Oral in- 18. Estepa JC, Lopez I, Mayer-Valor R, et al. What is your fection of weanling foals with an equine isolate of Law- diagnosis? Inflammatory and infiltrative disease of the colon. sonia intracellularis, agent of equine proliferative enteropa- J Am Vet Med Assoc 2005;227:1081–1082. thy. J Vet Intern Med. 2010;24:622–627. 19. Pease AP, Scrivani PV, Erb HN, et al. Accuracy of increased 9. Kalck KA. Inflammatory bowel disease in horses. Vet Clin large-intestine wall thickness during ultrasonography for di- North Am Equine Pract 2009;25:303–315. agnosing large-colon torsion in 42 horses. Vet Radiol Ultra- 10. Epstein K, Short D, Parente E, et al. Serial gastrointestinal sound 2004;45:220–224. ultrasonography following exploratory celiotomy in normal adult ponies. Vet Radiol Ultrasound 2008;49:584–588. 20. Jones SL, Davis J, Rowlingson K. Ultrasonographic find- 11. Epstein K, Short D, Parente E, et al. Gastrointestinal ul- ings in horses with right dorsal colitis: five cases (2000– trasonography in normal adult ponies. Vet Radiol Ultra- 2001). J Am Vet Med Assoc 2003;222:1248–1251. sound 2008;49:282–286. 21. Brianceau P, Chevalier H, Karas A, et al. Intravenous lido- 12. Jenei TM, García-Lo´pez JM, Provost PJ, et al. Surgical caine and small-intestinal size, abdominal fluid, and outcome management of small intestinal incarceration through the after colic surgery in horses. J Vet Intern Med 2002;16:736– gastrosplenic ligament: 14 cases (1994–2006). JAmVet 741. Med Assoc 2007;231:1221–1224. 22. Korolainen R, Ruohoniemi M. Reliability of ultrasonogra- 13. Buchanan BR, Sommardahl CS, Moore RR, et al. What is phy compared to radiography in revealing intestinal sand your diagnosis? Pyloric-duodenal intussusception. JAmVet accumulations in horses. Equine Vet J 2002;34:499–504. Med Assoc 2006;228:1339–1340. 23. Santschi EM, Slone DE Jr, Frank WM II. Use of ultrasound 14. Mogg TD, Hart J, Wearn J. Postpartum hemoperitoneum in horses for diagnosis of left dorsal displacement of the large and septic peritonitis in a Thoroughbred mare. Vet Clin colon and monitoring its nonsurgical correction. Vet Surg North Am Equine Pract 2006;22:61–71. 1993;22:281–284.

18 2012 ր Vol. 58 ր AAEP PROCEEDINGS

Orig. Op. OPERATOR: Session PROOF: PE’s: AA’s: 4/Color Figure(s) ARTNO: 1st disk, 2nd beb spencers 7 F1-3,5-10,12 3407