Small intestinal obstruction secondary to kinetic sand ingestion in a dog

Abstract

Objective

To describe a case of small intestinal obstruction secondary to kinetic sand ingestion in a dog.

Animal

An 11-year-old neutered male shih tzu dog with a 2-day history of anorexia.

Procedure

Abdominal radiographs revealed a small intestinal bowel loop dilated with radiopaque material, consistent with sand ingestion. The dog’s only sand exposure was to kinetic sand. After 8 h of medical management, radiographs were consistent with a small intestinal obstruction.

Results

The dog underwent exploratory laparotomy, which revealed distal jejunal and ileal distention with palpable soft foreign material that could not be milked into the colon. The sand was removed through a single enterotomy. The dog was discharged 4 d after surgery.

Conclusion and clinical relevance

The hydrophobic properties of kinetic sand may make it more likely than regular sand to cause intestinal obstruction that requires surgery. With the increasing popularity and availability of kinetic sand for domestic use, clinicians should have a high index of suspicion for kinetic sand impaction and secondary intestinal obstruction.

Sand impaction in dogs is an infrequently reported problem; however, it is likely seen more commonly in practice. Sand ingestion can cause severe enteritis as well as a small intestinal obstruction. Large intestinal impaction has also been reported (1). Small intestinal impactions can be treated medically or surgically (2,3). Medical management typically involves rehydration with intravenous (IV) fluids. In medically treated patients, close monitoring for resolution of impaction is necessary. Monitoring for the development of sepsis in these dogs is also vital, as the presence of sand can cause mucosal wall irritation and damage secondary to supraphysiologic intraluminal and intramural pressures (4). Surgical treatment involves removal of the sand either by milking the contents into the large intestine or via enterotomy. The mortality rate in dogs for removal of gastrointestinal foreign bodies has been reported to be < 1% with enterotomy (5). Of those requiring enterectomy, 26% had anastomotic leakage that significantly affected outcome (6), with the odds of enterectomy dehiscence being 6× the odds for enterotomy (7). In comparison, overall survival rates for sand impaction treated either medically or surgically have been reported to approximate 90% (3).

An 11-year-old neutered male shih tzu dog was brought to the emergency service of a tertiary referral hospital because of a possible intestinal obstruction. The dog had a 2-day history of anorexia with no vomiting or diarrhea. The dog had a history of ingesting foreign material and, 3 d before admission, ate a piece of paper. Also, the dog had a history of allergies but was otherwise healthy. Upon examination by the referring veterinarian, the dog was seen to be 5% dehydrated with a nonpainful, doughy abdomen and leakage of gelatinous, blue-grey-tinged fluid from the rectum. In-clinic serum biochemistry analysis revealed mild hyperglycemia [161 mg/dL; reference range (RR): 70 to 143 mg/dL], mild hyperproteinemia (8.3 g/dL; RR: 5.2 to 8.2 g/dL), and mild elevations in alkaline phosphatase (303 U/L; RR: 23 to 212 U/L) and alanine aminotransferase (161 U/L; RR: 10 to 125 U/L). Hematology revealed mild neutrophilia (13.34 K/μL; RR: 2.95 to 11.64 K/μL) and lymphopenia (0.78 K/μL; RR: 1.05 to 5.10 K/μL), consistent with a stress leukogram. A canine pancreatic lipase SNAP test was normal. Three-view abdominal radiographs revealed multiple loops of small bowel in the mid-abdomen that were dilated with radiopaque material. The gastric pylorus also contained the same radiopaque material, which appeared consistent with sand. Upon further questioning of the owner, the dog’s only sand exposure was to blue kinetic sand, a creative play item for the children in the house. The dog received subcutaneous (SC) fluids (24 mL/kg), ondansetron (0.48 mg/kg SC), and maropitant (1.2 mg/kg SC), and was then referred for possible surgery.

Upon presentation to the referral hospital, the dog’s physical examination findings were unchanged from those of the referring veterinarian. An abdominal-focused assessment with sonography for tracking did not show abdominal effusion. The dog was hospitalized and administered IV fluids using lactated Ringer’s solution (Vetivex; Dechra, Overland Park, Kansas, USA), 6 mL/kg per hour, to see if the small bowel material would move with rehydration. Follow-up radiographs obtained 8 h after starting IV fluids revealed most of the gastric material had advanced into the duodenum. However, the small bowel material had not visibly moved and there was now marked dilation cranial to the material (Figure 1). With a concern for ongoing obstruction based on progressive dilation and mismatch of the bowel on radiographs, and because the dog had by then been clinical for 2 d, it was decided to carry out an exploratory laparotomy.

Figure 1.

Recheck right lateral abdominal radiograph of an 11-year-old shih tzu dog.

The dog was taken to emergency surgery, where the distal jejunum and ileum were seen to be erythematous, bruised, and distended with palpable soft foreign material. The stomach was also markedly dilated with fluid. Intestinal milking was undertaken in an effort to move the foreign material into the colon. The material would not readily pass through the ileocolic junction. The attempt was discontinued due to the occurrence of some serosal tearing in the distal ileum and the risk of further iatrogenic injury. A jejunal enterotomy was completed and a large quantity of sand was removed through suction and lavage at the incision site (Figure 2). The surgeon noted greater difficulty and longer time involved to break down and remove the impaction with kinetic in comparison to normal sand. The enterotomy site was closed and tested for leakage; the section of bowel was noted to have good peristalsis and pulses and improved color, leaving the surgeon confident with the choice of enterotomy over a resection and anastomosis. A serosal patch over the enterotomy site was placed with an adjacent loop of jejunum using 2 lines of 3-0 polydioxanone simple interrupted sutures. Bupivacaine liposome (Nocita; Elanco, Greenfield, Indiana, USA), 6.3 mg/kg, was infused into the SC incision upon closure. The dog recovered from anesthesia uneventfully.

Figure 2.

Photograph of the enterotomy site in an 11-year-old shih tzu dog, showing kinetic sand removal.

Methadone (Akorn, Lake Forest, Illinois, USA) administration was continued after surgery at 0.2 mg/kg, IV, q6h initially and then as needed for pain. Ampicillin + sulbactam (Piramal Critical Care, Bethlehem, Pennsylvania, USA), 30 mg/kg, IV, q8h, was started at the time of surgery; and enrofloxacin (Baytril; Elanco US, Shawnee, Kansas, USA), 10 mg/kg, IV, q24h, was added postoperatively. It has been reported that 63% of dogs with sand ingestion had dual antibiotic coverage (3). The decision for addition of antibiotics was based on evidence of serosal tearing at the time of surgery and risk of particulate contamination of the abdomen, given the difficulty of sand removal. There was also concern for mucosal damage and potential bacterial translocation secondary to the inherently abrasive properties of sand. After surgery, the dog developed blood-tinged, sandy diarrhea. Continued treatments included lactated Ringer’s solution, IV, at a variable rate depending upon the level of hydration; maropitant (Cerenia; Zoetis, Kalamazoo, Michigan, USA), 1 mg/kg, IV, q24h; ondansetron (Fosun Pharma, Princeton, New Jersey, USA), 0.5 mg/kg, IV, q8h; and sucralfate (Par Pharmaceutical, Chestnut Ridge, New York, USA), 62 mg/kg, PO, q8h. Two days after surgery, capromorelin (Entyce; Elanco, Greenfield, Indiana, USA), 3 mg/kg, PO, q24h, was started due to anorexia. Later that day, the dog developed regurgitation and was given metoclopramide (Hospira, Lake Forest, Illinois, USA), 2 mg/kg per day, IV continuous rate infusion; and erythromycin (Hospira), 0.5 mg/kg, IV, q8h. Due to persistent anorexia 3 d after surgery, a nasogastric (NG) tube was placed to begin enteral feedings using Royal Canin GI Low Fat Liquid (Royal Canin, North Sioux City, South Dakota, USA) at 1/4 resting energy requirements. Four days after surgery, the dog’s appetite was improving, and due to financial concerns, was discharged to continue both oral and NG tube feedings at home. Six days after surgery, the dog was rechecked at the authors’ hospital. The NG tube was removed as the dog’s appetite had returned to normal. The dog was noted to be doing well clinically and at home.

Kinetic sand is regular sand coated with polydimethylsiloxane (PDMS), a silicone oil (8). The PDMS gives kinetic sand viscoelastic properties (9). The resulting product is hydrophobic, sticks to itself, and does not dry out. Kinetic sand is currently used in various educational and therapeutic settings, from helping children on the autism spectrum to those with attention deficit hyperactivity disorder (8,10). It is also becoming a more common play item for families with young children, as the sand feels wet and can be molded into various shapes, but does not stick to hands and so is easy to clean up. With the popularity of kinetic sand increasing, more animals are exposed, leading to more reported cases of ingestion. From 2002 to 2022, the ASPCA Animal Poison Control Center opened 536 cases regarding kinetic sand ingestion, with 80 of those in 2022 alone (Nicole Martin, ASPCA; personal communication, 2022). Kinetic sand is nontoxic, as PDMS is chemically inert (9). Yet, any sand ingested in a large enough quantity can lead to intestinal impactions. Because kinetic sand sticks to itself and is hydrophobic, even a small amount can act like a solid foreign body — less likely to break apart in water and potentially more likely to result in intestinal obstruction.

A previous retrospective study showed 50% of sand impactions could be treated without requiring surgery (3). However, when looking at small intestinal obstructions due to all causes, < 20% resolved with medical management (11). Once medical management is started, there is no recommended time period to wait before proceeding with surgery, as this is very much dependent on each individual patient. One study showed no difference in outcome between immediate and delayed surgery (12). In this dog, medical management was attempted for ~8 h before electing surgery, with the decision for surgery based on recheck radiographs. On radiographs in dogs, if the ratio of the maximum small intestinal diameter to the midbody height of the 5th lumber vertebra is > 2.4, then intestinal obstruction is probable (13). Initial radiographs of this dog showed the ratio to be 2.8, and recheck radiographs taken 8 h later showed a ratio of 2.9. Compared to regular sand, the inherent properties of kinetic sand, which cause it to hold together and not dry out, may contribute to a higher likelihood of causing an intestinal obstruction and failing medical management.

Recently, the use of polyethylene glycol solution was reported to resolve sand impaction in 3 dogs (14). Polyethylene glycol is a nonabsorbable compound that acts as an osmotic laxative (15). The hydrophobic properties of kinetic sand could, in theory, make it less susceptible to the effectiveness of osmotic laxatives. In this dog, the decision for surgery was based on the fact that the dog was anorexic for 2 d before presentation, the persistent obstructive pattern seen on recheck radiographs, and the unknown responsiveness of kinetic sand to continued medical management.

In conclusion, this case highlights the unique properties of kinetic sand, which may make kinetic sand impaction more likely than regular sand impaction to cause an intestinal obstruction and require surgery. With the increasing popularity and availability of kinetic sand for domestic use, clinicians should have a high index of suspicion for kinetic sand impaction and secondary intestinal obstruction.