Diagnostic ultrasonography of the mature equine abdomen

Comparison of transrectal and transabdominal transducers for use in fast localized abdominal sonography of horses presenting with colic

Abdominal ultrasonography is valuable in the diagnosis of equine colic. Fast localized abdominal sonography of horses (FLASH) enables practitioners with limited experience to perform ultrasonography in emergency settings. However, many practitioners only possess rectal format linear array transducers (RFLT). The hypotheses are: (a) A low frequency curvilinear transducer (LFCT) and RFLT will detect free abdominal fluid and abnormal small intestinal loops with similar frequency during FLASH, and (b) there will be a difference between the transducers for detection of gastric abnormalities and nephrosplenic entrapment. The objective is to compare transcutaneous abdominal ultrasonographic detection of abnormalities in horses presenting with colic using a LFCT and RFLT. Twenty-four horses requiring FLASH for investigation of colic were enrolled. Horses that were too painful to undergo transcutaneous abdominal ultrasonographic examination were excluded. A single investigator performed FLASH on all horses using a RFLT, while one of three other clinicians simultaneously performed FLASH using a LFCT. Comparison of abnormal findings between the two transducers was performed using Chi square, Fisher's exact or Wilcoxon tests. The incidence of identification of abnormal findings was similar between the two transducers for all comparisons except the visibility of the left kidney and stomach (kidney LFCT 81.25% vs. RFLT 22.92%, stomach LFCT 87.5% vs. RFLT 62.5%). While there are limitations to using a RFLT to identify nephrosplenic entrapment of the colon and detection of the stomach, it reliably detects other common abnormalities, including peritoneal effusion, lesions of the small intestine, and changes to the wall of the large colon and cecum.

Imaging of the Urinary Tract

This article provides a comprehensive review of imaging techniques used to evaluate the equine urinary tract. This overview includes officially recognized modalities and new applications reported in the most current literature. Technical aspects and indications for use of endoscopy and ultrasonography are highlighted. Normal endoscopic and ultrasonographic appearance of the upper and lower urinary tract is described, with characterization of common abnormalities found in patients with hematuria, stranguria, and renal failure. Visual examples of several pathologic conditions from clinical cases are provided. An outline of the main features, potentials, and limitations of radiography, nuclear scintigraphy, and computed tomography is provided.

Reference Values and Repeatability of Transabdominal Ultrasonographic Gastrointestinal Tract Thickness and Motility in Healthy Donkeys (Equus asinus)

The present study aimed to provide reference ranges for the wall thickness and motility pattern of the gastrointestinal tract from a sample of donkeys (Equus asinus) population using B-mode ultrasonography. In the present study, 30 clinically healthy donkeys (Equus asinus) (15 males and 15 females), aged 2-20 year old and weighed 100-280 kg were randomly selected for B-mode ultrasonographic scanning of the abdomen. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was assessed. Moreover, the motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was evaluated over a period of 3 minutes. Abdominal ultrasonographic scanning of the gastrointestinal tract of healthy donkeys explored that the stomach, duodenum, jejunum, left colon, right colon, and cecum could be visualized easily. The wall thickness of the stomach, duodenum, jejunum, left colon, right colon, and cecum was 7.0 ± 0.9 mm, 3.3 ± 1.0 mm, 5.4 ± 0.6 mm, 5.1 ± 0.5 mm, 5.4 ± 0.5 mm, and 5.4 ± 0.6 mm, respectively. The thickest part of the gastrointestinal tract is the stomach, whereas the thinnest part is the duodenum. The motility pattern of the duodenum, jejunum, left colon, right colon, and cecum was 7.7 ± 1.3 contractions/3 minutes, 6.9 ± 1.1 contractions/3 minutes, 4.1 ± 1.2 contractions/3 minutes, 5.5 ± 1.3 contractions/3 minutes, and 4.0 ± 0.8 contractions/3 minutes, respectively. Both the duodenum and jejunum contractions were significantly higher than that of the left colon, right colon, and cecum. This is the first study reporting the reference values for both the wall thickness and motility pattern of the gastrointestinal tract in healthy donkeys (Equus asinus) in Egypt. Good knowledge of these standard and reference values of the wall thickness and motility pattern of gastrointestinal tract structures represents a step in the early diagnosis of the gastrointestinal disorders, including colic in such animal species.

Preoperative factors associated with resection and anastomosis in horses presenting with strangulating lesions of the small intestine

OBJECTIVE

To determine if preoperative and intraoperative clinical variables correlate with resection and anastomosis (RA) in horses presenting with strangulating small intestinal (SI) lesions.

STUDY DESIGN

Retrospective case series.

ANIMALS

Horses undergoing exploratory celiotomy for a strangulating SI lesion (n = 243).

METHODS

The records of horses undergoing surgical correction for strangulating SI lesions from January 1, 2000 to December 31, 2017 were reviewed. Horses were categorized as treated with RA or not treated with RA. Obtained information included history, signalment, clinical findings, diagnostic test results, intraoperative findings, and survival to discharge. Univariable and multivariable analyses were used to compare data between horses treated with RA vs those not treated with RA (P = .05).

RESULTS

In total, 172 SI lesions were resected, and 71 were not resected. Horses that had gastric reflux at admission to the hospital (odds ratio [OR] 5.56; 95% CI 1.76, 17.59) and horses with amotile SI according to abdominal ultrasonography (OR 9.69; 95% CI 3.09, 30.37) were more likely to undergo RA. Increased difference between peritoneal fluid and blood lactate was higher in horses that underwent RA (OR 1.55; 95% CI 1.12, 2.13). Survival to hospital discharge was lower in the group of horses that underwent RA compared with horses that did not undergo RA.

CONCLUSION

Resection and anastomosis of strangulating SI lesions was associated with several preoperative variables.

CLINICAL SIGNIFICANCE

This study highlights the value of preoperative diagnostic procedures in aiding intraoperative decision making and prognostication in horses presenting with strangulating SI lesions.

Ultrasonography guidance for total splenectomy in donkeys

There are varieties of surgical approaches reported for equine splenectomy and all of them were dealing with the most reachable situation of splenic hilus and easy handling of the spleen. The aim of this work was to establish the normal ultrasound parameters of spleen in donkeys (normal echogenicity, hilus situation, topographic location and correlation with neighboring organs) as a guide to select the best approach for total splenectomy in donkeys. Splenic ultrasound was carried out on six normal donkeys before experimental total splenectomy in the standing position. The splenic topographic location was recorded among 4 rows including 30 squares. These animals were divided into two groups according to the surgical approach of total splenectomy. Total splenectomy after left 16^th and 17^th ribs partial resection in standing position was carried out in group1 and group 2, respectively. Ultrasonographically, the spleen had homogenously echogenic pattern and appeared hyperechoic to the liver. Only one third of the spleen was located in front of the 16^th rib where the hilus and splenic blood vessels were nearly under the 16^th rib. The splenic artery and splenic vein were ultrasonographically visualized between the left 16^th and 17^th ribs 10-15 cm from dorsal midline. This area was the site of the important ligation during total splenectomy. In conclusion, ultrasonography guidance for total splenectomy in donkeys assisted the surgical findings and proved that technique following partial resection of the 17^th rib at the standing position is the most convenient surgical approach for total splenectomy in donkeys.

Vergleich rektaler und sonographischer Untersuchungsbefunde bei der Kolik des Pferdes

Gegenstand und Ziel: Neben der routinemäßigen Untersuchung des Kolikpatienten (klinische inklusive rektale Untersuchung), kommt zunehmend die Sonographie zur Anwendung. Ziel der Studie war, die Befunde der rektalen Untersuchung mit denen der sonographischen Untersuchung bei unterschiedlichen Kolikerkrankungen zu vergleichen. Material und Methoden: In einer retrospektiven Studie wurden die Patientendaten von Pferden mit Koliksymptomen der Jahre 2012 und 2013 der Chirurgischen Tierklinik Leipzig ausgewertet. Die anhand der rektalen und sonographischen Untersuchung gestellten Verdachtsdiagnosen wurden gruppiert und den Diagnosen (Goldstandard) der operativen Behandlung bzw. der pathologischen Untersuchung gegenübergestellt. Bei konservativ behandelten Tieren wurde nur bei eindeutigem rektalem Befund eine definitive Diagnose formuliert. Für beide diagnostische Verfahren erfolgte die Ermittlung von Sensitivität, Spezifität, positivem und negativem Vorhersagewert. Ergebnisse: Bezüglich der Diagnostik des Dünndarmverschlusses erwies sich die sonographische Untersuchung als deutlich sensitiver als die rektale Befunderhebung (97,1%; 50,7%). Eine bessere Sensitivität erzielte die sonographische Untersuchung auch bei der Längsachsendrehung des großen Kolons (63,2% vs. 26,3%) und bei der Verlagerung des großen Kolons in den Milz-Nieren-Raum (90,9% vs. 72,7%). Im Fall von Kolonverlagerungen bzw. Verstopfungen des großen Kolons war die rektale Untersuchung weitaus sensitiver als die sonographische Untersuchung (96,5% vs. 8,8%) bzw. (93,6% vs. 29,8%). Schlussfolgerung und klinische Relevanz: Besonders schwerwiegende Erkrankungen, wie der Dünndarmverschluss und die Längsachsendrehung des großen Kolons, werden mithilfe der Sonographie sicherer erkannt als durch die rektale Untersuchung. Deshalb sollte unter Klinikbedingungen auf die sonographische Untersuchung des Kolikpatienten nicht verzichtet werden. Bei der Diagnostik von Verlagerungen und Verstopfungen des großen Kolons sowie von Blinddarmerkrankungen erweist sich hingegen die transrektale Palpation gegenüber der Ultraschalluntersuchung überlegen.

Correlation between capillary oxygen saturation and small intestinal wall thickness in the equine colic patient

The surgical evaluation of haemorrhagic infarcted intestine and the decision for or against bowel resection require a lot of experience and are subjective. The aim of this prospective, clinical study was to examine the correlation between oxygen saturation and small intestinal wall (IW) thickness, using two objective methods. In 22 colicky horses, the blood flow, oxygen saturation and relative amount of haemoglobin were measured intraoperatively via laser Doppler and white light spectroscopy (O2C, oxygen to see, LEA Medizintechnik) at six measuring points (MPs) in small and large intestines. Furthermore, the IW thickness was measured ultrasonographically. Nine of 22 horses had an increased small IW thickness greater than 4 mm (Freeman 2002, Scharner and others 2002, le Jeune and Whitcomb 2014) at measuring point 1 (MP1) (strangulated segment), four horses had a thickened bowel wall at measuring point 3 (MP3) (poststenotic) and one at measuring point 2 (MP2). The oxygen saturation was 0 at MP1 in six horses, at MP3 in two horses and at MP2 (prestenotic) in one. Oxygen saturation and small IW thickness were independent of each other at MP1 and MP2. At MP3, the two parameters were negatively correlated. In summary, it is not possible to draw conclusions about oxygen saturation based on IW thickness.