Abdominal auscultation in the detection of experimentally induced gastrointestinal sand accumulation

The effects of bit chewing on borborygmi, duodenal motility, and gastrointestinal transit time in clinically normal horses

OBJECTIVE

To determine the influence of bit chewing on gastrointestinal transit in clinically normal horses.

STUDY DESIGN

Prospective crossover designed study.

ANIMALS

Six healthy adult horses.

METHODS

Horses were assigned randomly to treatment (apple flavored bit) and control (no-bit) groups and studied for 2 × 1-week trial periods with a 2-week washout period between trials. Horses were fasted for 24 h and slowly refed over 3 days. The bit was placed for 20 min every 6 h. Duodenal contractions and borborygmi auscultations were evaluated every 12 h, approximately 5 min following bit placement. Gastrointestinal total transit time (GI TTT) was measured by administering 200 colored beads via stomach tube and then collected in the manure until 50% and 80% were recovered. Measured variables were compared using an ANOVA or Wilcoxon signed-rank test and the P value was noted.

RESULTS

The GI TTT was shortened in the bit chewing group (median: 106.37 h, range: 70-171 h) compared to the no-bit group (median: 170.1 h, range: 149-186 h) (P = .0156) at 80% bead passage (only 4/6 horses passed 80%). Borborygmi (P = .8193), duodenal contractions (P = .2605), and 50% bead passage (P = .0781) showed no differences.

CONCLUSION

Bit chewing was safe, inexpensive, and well tolerated. Bit chewing shortened GI TTT and might be an adjunct therapy to augment GI TTT. Further clinical studies are warranted.

CLINICAL SIGNIFICANCE

Ileus is a common complication following equine abdominal surgery with no current consistently successful treatment. Bit chewing may be a simple and inexpensive way to augment progressive GI motility.

Carboxymethylcellulose and psyllium effects in sand output of horses with asymptomatic sand accumulation

ABSTRACT The aim of this study was to evaluate the effects of Psyllium (PSY) and Carboxymethylcellulose (CMC) administration on fecal elimination of sand in horses with asymptomatic sand accumulations. Eight horses were selected from sandy areas and randomly divided into 2 groups of four animals. The subjects were treated either with CMC or PSY. The presence of intestinal sand was confirmed through radiography and glove sedimentation test. The study was performed in two phases, with a 7-day interval. In phase I, all the animals received 8 liters of warm water; in phase II, the CMC group received 8 liters of water + 1g/kg of CMC, whereas the PSY group received 8 liters of water + 1g/kg of PSY. All administrations were performed through nasogastric intubation and fractionated in 2 equal volume administrations with an interval of two hours. General and specific physical examination of the digestive system were performed in conjunction with abdominal ultrasonography before the administrations and after 6, 12, 24, 36 and 48 hours, aiming to evaluate intestinal motility and presence of sand. All the feces eliminated by the animals within the 72 hours following the administrations were quantified, diluted and sedimented in order to calculate the sand output (g/kg of feces). All the animals were also subjected to radiographic examination to quantify sand accumulation prior to phase I and after 72 hours of phases I and II. No adverse effects were observed after the treatments. It was possible to notice higher sand elimination in both groups during the phase I, whereas no difference was observed in sand elimination rates between the groups in phase II. The radiographic scores presented differences between the initial timepoint and 72h in phases I and II for both groups. Based on the sand elimination rates and radiographic score, this study demonstrated that sand output was greater after administration of water alone, compared to CMC and Psyllium, leading to the inference that removal of the sandy environment and prevention of sand re-ingestion are effective measures for the elimination of sand from the colon of horses with asymptomatic sand accumulations.

Owner-Reported Clinical Signs and Management-Related Factors in Horses Radiographed for Intestinal Sand Accumulation

Clinical problems related to intestinal sand accumulation in horses are common in certain geographic areas, but the clinical signs appear nonspecific and the course of the accumulation remains somewhat obscure. This study examined the association between the presence and size of intestinal sand accumulations and owner-reported clinical signs, management, and feeding practices, as well as behavioral patterns in horses with radiographic diagnosis of sand accumulation. Owners of the horses filled in an online questionnaire. A total of 447 responses met the inclusion criteria. The size of the sand accumulation detected in the radiographs was not significantly associated with the age, body condition score, sex, or use of the horses. Horses reported to have expressed colic had significantly larger sand accumulations than those without this sign, and a similar association was detected in horses with poor performance. The highest odds ratio for sand accumulation was for the combination of colic and poor performance, followed by colic combined with diarrhea/loose feces or hyperesthesia to touch of the abdominal wall. Larger sand accumulations were detected in greedy horses that eat all their roughage, whereas dominant position in group hierarchy was associated with less sand. The possibility of abdominal sand accumulation should be considered as one of the differentials in horses with multiple owner-reported clinical signs such as colic, poor performance, diarrhea, and hyperesthesia to touch of the abdomen.

Clinical findings and management of 153 horses with large colon sand accumulations

OBJECTIVE

To determine the influence of radiographic quantification of sand accumulation on the medical versus surgical management of large colon sand accumulations. To compare short- and long-term outcomes and complications associated with medical and surgical management of these horses.

STUDY DESIGN

Retrospective.

SAMPLE POPULATION

A total of 153 horses.

METHODS

Medical records and abdominal radiographs of horses presented for colic between 2004 and 2014 were reviewed. Severity of sand accumulation was quantified by tracing and measuring a region of interest with a commercial software program. Breed, weight, amount of sand, presence of diarrhea at presentation, treatment, and the development of complications were recorded.

RESULTS

Records from 153 horses were reviewed. The mean cross-sectional area of sand accumulation was 692.9 cm² (median = 658.7 cm² , 84.6-1780.7 cm² ). Increased accumulation of gas on radiographs and abnormal transrectal examination findings were associated with an increased likelihood of surgery. The most common complication was the development of diarrhea (20.3%) with only 4 (2.6%) horses positive for Salmonella spp. Horses had a favorable prognosis, with 94.8% of horses treated medically and 94.7% of those treated surgically surviving to discharge.

CONCLUSION

Increased accumulation of gas on radiographs and transrectal palpation of impaction or intestinal gas distension increase the likelihood of surgery. Both medical and surgical treatments carry a good prognosis.

CLINICAL RELEVANCE

The sheer quantity of sand is not a factor when determining surgical intervention. Attention should be paid to the presence of increased gas accumulation on rectal or radiographic examination.

Comparison of psyllium feeding at home and nasogastric intubation of psyllium and magnesium sulfate in the hospital as a treatment for naturally occurring colonic sand (geosediment) accumulations in horses: a retrospective study

BACKGROUND

Ingestion of geosediment (further referred as sand) may cause weight loss, diarrhea and acute or recurrent colic in horses. Our aim was to compare the efficacy of three treatment protocols in clearing colonic sand accumulations in clinical patients. This retrospective clinical study consisted of 1097 horses and ponies, which were radiographed for the presence of colonic sand. Horses included to the study (n = 246) were displaying areas of sand in the radiographs of ≥75 cm² and were treated medically monitoring the response with radiographs. The horses were assigned into three groups based on the given treatment: Group 1 was fed psyllium [1 g/kg body weight (BW)] daily at home for a minimum of 10 days (n = 57); Group 2 was treated once with psyllium or magnesium sulfate by nasogastric tubing followed by daily feeding of psyllium (1 g/kg BW) at home for a minimum of 10 days (n = 19), and Group 3 was treated by daily nasogastric tubing for 3-7 days with psyllium and/or magnesium sulfate (1 g of each/kg BW) (n = 170).

RESULTS

The initial area of sand did not differ significantly between the treatments. Group 3 had significantly less residual sand than Groups 1 and 2, and the proportion of resolved horses was higher in Group 3 than in Groups 1 and 2.

CONCLUSIONS

Daily nasogastric tubing with psyllium and/or magnesium sulfate for 3-7 days removes large accumulations of sand from the colon in horses more effectively than feeding psyllium for at least 10 days.

Ambulatory medicine in equine practice

The scope of medical problems encountered by the equine ambulatory practitioner is immense; there is a wealth of information available to ambulatory practitioners pertaining to specific medical topics. It is certainly possible to practice high-quality equine medicine in a field setting. However, hospital referral should be offered to clients for conditions not conducive to successful treatment in the field. Prompt referral of difficult cases is a sign that the practitioner wants the best treatment for the patient and is often gladly accepted by the client. When surgical or hospital referral is not an option, it is imperative that the ambulatory practitioner not only offer humane alternatives but also inform and educate horse owners on equine suffering and welfare issues so that clients do not have unreasonable expectations of a positive outcome.

Radiographic parameters for diagnosing sand colic in horses

BACKGROUND

Ingestion of sand can cause colic, diarrhoea and weight loss in horses, but these signs are unspecific and can have many other causes. The amount of sand that induces disease may vary between individuals. To avoid over-diagnosing, it is important to determine the amount of sand that can be found in horses without clinical signs of gastrointestinal disease. The aim of this study was to use previously suggested parameters for establishing a radiographic diagnosis of sand colic, and compare these findings between a sand colic group and a control group.

METHODS

Abdominal radiographs were obtained in 30 horses with a complaint unrelated to the gastrointestinal tract. In addition, archived abdominal radiographs of 37 clinical cases diagnosed with sand impaction were investigated. The size of the mineral opacity indicative of sand in the abdomen was measured and graded according to a previously published protocol based on height and length. Location, homogeneity, opacity and number of sand accumulations were also recorded.

RESULTS

Twenty out of 30 control horses (66%) had one or more sand accumulations. In the present study; height, length and homogeneity of the accumulations were useful parameters for establishing a diagnosis of sand colic. Radiographically defined intestinal sand accumulation grades of up to 2 was a common finding in horses with no clinical signs from the gastrointestinal tract whereas most of the clinical cases had much larger grades, indicating larger sand accumulations.

CONCLUSION

Further work to establish a reliable grading system for intestinal sand content is warranted, but a previously proposed grading system based on measurements of height and length may be an alternative for easy assessment of sand accumulations in the meantime. The present study indicates that a grade 1 - 2 sand accumulation in the intestine is a frequent finding in horses. When working up a case with clinical signs from the gastrointestinal tract, one or more accumulations of this grade should not be considered the cause until other possibilities have been ruled out.

Objective radiographic assessment of abdominal sand accumulation in horses

Gastrointestinal sand accumulation is a common cause of equine colic. Subjective assessment of sand accumulation on abdominal radiographs has been used as a diagnostic aid; however, there is poor correlation between clinical, diagnostic, and surgical findings. The purpose of this study was to develop an objective method of assessing radiographic sand accumulation in order to improve the diagnostic utility of radiography for sand colic. Fifty-one equine abdominal radiographic examinations were reviewed, with approximately half of the imaged patients having a clinical diagnosis of sand colic. Initially, four observers independently reviewed these radiographic studies to subjectively decide whether or not sand accumulation was sufficient to cause colic. Subsequently, an objective scoring system was developed using various radiographic parameters that yielded a score ranging from one to 12 for quantity and apparent density of sand accumulation. Inter- and intraobserver results using the subjective scoring method had significant differences among all observers. Subjective assessment was also deemed to be inaccurate for colic prediction. Using the objective scoring system, there were no significant differences between or within the observers' results. A score of seven out of 12 was found to have an 83% likelihood of being associated with a positive diagnosis of sand colic. The designed objective scoring method creates a more uniform and accurate method to assess the sand accumulation.

Evaluation of equine cecal motility by ausculation, ultrasonography and electrointestinography after jejunocecostomy

OBJECTIVE

Horses often suffer reduced intestinal motility after jejunocecostomy. Therefore, accurate evaluation of intestinal motility is important for the prevention, diagnosis and treatment of this condition. The purpose of this study was to evaluate intestinal motility in horses after jejunocecostomy using three different methods, i.e. auscultation, ultrasonography and electrointestinography.

ANIMALS

Six healthy thoroughbreds were used in this study. They were subjected to jejunocecostomy.

PROCEDURE

Bowel sounds in the right paralumbar fossa were assigned a score of 0-3 for intestinal motility evaluation by auscultation, and the number of cecal contractions during a 3-min period were counted by ultrasonography. Electrointestinography (EIG) was used to measure percutaneous potential of the cecum.

RESULTS

We identified three specific postoperative periods: the period of reduced intestinal motility (postoperative day 1 to day 2), in which intestinal motility declined, the unstable period (day 3 to day 7), in which intestinal motility partially recovered, and the full recovery period (day 8 to day 31), in which intestinal motility returned to preoperative state. Careful management was found to be especially important during the period of reduced intestinal motility and the unstable period. We found that, in healthy horses that underwent jejunocecostomy, it takes approximately one month for the cecum to return to normal motility patterns observed before surgery.

CONCLUSION

We have shown in this study that evaluation of intestinal motility after jejunocecostomy in horses by EIG is more objective and provides more details than evaluation by auscultation or ultrasonography.

Risk factors for faecal sand excretion in Icelandic horses

REASONS FOR PERFORMING STUDY

Sandy soil is often mentioned as a risk factor in the development of sand-related gastrointestinal disease (SGID) in the horse. There are other variables, but few studies confirm any of these.

OBJECTIVE

To investigate soil type, pasture quality, feeding practice in the paddock, age, sex and body condition score as risk factors for sand intake in the horse.

METHODS

Faeces were collected from 211 Icelandic horses on 19 different studs in Denmark together with soil samples and other potential risk factors. Sand content in faeces determined by a sand sedimentation test was interpreted as evidence of sand intake. Soil types were identified by soil analysis and significance of the data was tested using logistic analysis.

RESULTS

Of horses included in the study, 56.4% showed sand in the faeces and 5.7% had more than 5 mm sand as quantified by the rectal sleeve sedimentation test. Soil type had no significant effect when tested as main effect, but there was interaction between soil type and pasture quality. Significant interactions were also found between paddock feeding practice and pasture quality.

CONCLUSION

To evaluate the risk of sand intake it is important to consider 3 variables: soil type, pasture quality and feeding practice. Pasture quality was identified as a risk factor of both short and long grass in combination with sandy soil, while clay soil had the lowest risk in these combinations. Feeding practice in the paddock revealed feeding directly on the ground to be a risk factor when there was short (1-5 cm) or no grass. Also, no feeding outdoors increased the risk on pastures with short grass, while this had no effect in paddocks with no grass. More than 50% of all horses investigated in this study had sand in the faeces.

POTENTIAL RELEVANCE

The identification of risk factors is an important step towards prevention of SGID. Further research is necessary to determine why some horses exhibit more than 5 mm sand in the sedimentation test and whether this is correlated with geophagic behaviour.

Reliability of ultrasonography compared to radiography in revealing intestinal sand accumulations in horses

In order to investigate the reliability of ultrasonography in revealing intestinal sand accumulations, the cranioventral parts of the abdomen of 32 horses (age 3-20 years) with signs suggestive of gastrointestinal sand were examined radiographically and ultrasonographically. The amount of sand and its localisation, relative to the ventral abdominal wall, were evaluated radiographically and graded (scale 0-4). Motility of the intestine and whether it was lying against the ventral abdominal wall were evaluated ultrasonographically and the findings summed and graded (scale 0-3) to express the likelihood of the presence of sand. The ultrasonographic and radiographic grades were significantly associated. Out of 14 horses with a moderate or large ventral sand accumulation radiographically, 13 (92.9%) had a positive sand finding ultrasonographically. Out of 8 horses with no signs of sand radiographically, 7 were considered negative for sand ultrasonographically. The specificity of ultrasonography in detecting sand accumulations was 87.5% (7/8) and the sensitivity 87.5% (21/24). Small and more dorsally located accumulations were more difficult to detect ultrasonographically. Of the horses with a small or moderate amount of sand relatively ventrally or only a small part of sand close to the ventral abdominal wall, 70% (7/10) were considered suggestive or positive for sand ultrasonographically. The ventral aspect of sand accumulations was hyperechoic, causing varying acoustic shadowing and the intestine had decreased or absent motility. Ultrasonography revealed the length of the accumulations but gave very limited information of their height. Ultrasonography is a practical and reliable method for detecting sand accumulations but it cannot replace radiography.

Abdominal radiography in monitoring the resolution of sand accumulations from the large colon of horses treated medically

This retrospective study consisted of 14 horses (age 6 weeks-12 years) with radiographically evident sand accumulations cranioventrally in the abdomen and clinical signs suggestive of sand enteropathy. The horses were treated medically and resolution of sand was monitored radiographically. Routine treatment consisted of psyllium mucilloid, combined with magnesium sulphate and/or mineral oilif needed. Initially, the number, size and shape of the sand accumulations showed large variation and the response to therapy was not predictable based on the initial appearance of the accumulation. In 2 foals, some of the sand was passed and the rest was mixed with other intestinal contents within 2-4 days. Even large accumulations disappeared in 2-4 days with psyllium alone or combined with mineral oil in 4 horses. In another 4 horses, the size of the accumulations decreased but varying amounts remained approximately at the same site, despite treatment for 1-4 weeks, and all these horses also had either gastric or large colon impaction. Three horses had a limited response to psyllium treatment, but the accumulation resolved with repeated doses of magnesium sulphate, with or without mineral oil. One horse did not respond to prolonged laxative treatment but the accumulation resolved on pasture. Clinical improvement was not necessarily related to the resolution of sand. Radiography of the cranioventral abdomen was found to be a useful means for monitoring the resolution of sand and confirming the effect of medical treatment in removing sand from the large colon in the horse.

Failure of psyllium mucilloid to hasten evaluation of sand from the equine large intestine

OBJECTIVE

To examine the efficacy of psyllium mucilloid in evacuating sand from the equine large intestine.

ANIMALS

12 clinically healthy pony geldings.

PROCEDURE

Twelve ponies were assigned to 2 groups of six each. One group was treated with psyllium and the second was a control group. All ponies had an exploratory celiotomy and 10 g/kg body weight of sand was placed into the cecum. Ponies were fed a grain mixture alone at 1 g/kg (controls), a grain mixture plus psyllium pellets, each at 1 g/kg body weight (3 ponies), or fed a grain mixture and given psyllium powder by nasogastric tube at 1 g/kg body weight divided into two daily doses in 3 L of water (3 ponies). Radiographs were taken on days 1 (3 per group), 5 (all ponies), and 11 (3 per group) to monitor sand transit through the large intestine. Ponies were euthanatized 11 days after surgery. Sand was collected from the contents of the cecum, ventral colon, dorsal colon, and small colon. Dry weight of the recovered sand was compared between the two treatment groups as a percentage of the dry weight of sand placed in the cecum.

RESULTS

No significant differences were detected in the mean percentage of sand recovered between the two treatment groups (P < .05), with 39.2% recovered in ponies treated with psyllium and 27.4% recovered in control ponies.

CLINICAL RELEVANCE

Psyllium mucilloid had no apparent effect on sand evacuation from the equine large intestine. When intake of sand is prevented, the equine large intestine can reduce and possibly eliminate its sand burden.