Objective radiographic assessment of abdominal sand accumulation in horses

Psyllium supplementation is associated with changes in the fecal microbiota of horses

OBJECTIVE

Prophylactic supplementation of psyllium husk is recommended to enhance passage of ingested sand from the gastrointestinal tracts of horses. We hypothesized that psyllium supplementation would increase fecal sand passage and favorably alter bacterial populations in the hindgut. Six yearlings and six mature mares were fed a psyllium supplement in the diet daily for seven days. Voluntarily-voided feces were collected over the course of 29 days, prior, during, and after treatment. Feces were analyzed for acid detergent fiber (ADF) and acid detergent insoluble ash analyses. Microbial DNA was also isolated, and the V4 region of the 16S ribosomal RNA gene was PCR-amplified and sequenced using MiSeq technology.

RESULTS

Fecal ADF concentration was greater in adults while silica concentration was greater in yearlings. Mature mare fecal ADF decreased during and just after supplementation but thereafter increased. No changes in silica levels were noted in either group over time. Fecal microbial population phylogenetic diversity was greatest mid-supplementation and lowest at 11 days post-supplementation. Functional profiles of the microbial communities presented some benefits for psyllium supplementation. These findings provide compelling evidence for further detailed studies of prophylactic psyllium supplementation.

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.

Comparison of the effects of enteral psyllium, magnesium sulphate and their combination for removal of sand from the large colon of horses

Prospective studies documenting the efficacy and side effects of medical treatment for colonic sand accumulation in horses are limited. The purpose of the study was to compare the effect of enteral administration of magnesium sulphate (MgSO4), psyllium mucilloid (psyllium), and a combination of MgSO4 and psyllium on the evacuation of large accumulations of sand in the large colon of adult horses. Thirty-four horses with naturally acquired, large sand accumulations (>5 cm × 15 cm) identified on abdominal radiography were randomly allocated to one of three treatment groups: (1) 1 g/kg psyllium (n = 12); (2) 1 g/kg MgSO4 (n = 10), or (3) their combination (n = 12). Treatments were administered once a day via nasogastric intubation and continued for a total of 4 days. Lateral radiographs of the ventral abdomen were repeated on day 4 of treatment. If the area of sand in the radiographic image was <25 cm(2) on day 4, the sand accumulation was considered resolved. Of 12 horses treated with a combination of psyllium and MgSO4, nine evacuated the sand from the ventral colon within 4 days. In comparison, only 3/12 horses treated with psyllium and 2/10 horses treated with MgSO4 resolved (both significantly different from the combination; P <0.05). Large accumulations of sand in the large colon of horses can be treated medically. Administering a combination of psyllium and MgSO4 via nasogastric intubation once daily for a total of 4 days was a more effective treatment than either constituent alone.

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.