Abstract
Case Description—A 5-year-old castrated male Vietnamese pot-bellied pig (Sus scrofa) was evaluated because of anorexia, vomiting, diarrhea, and weight loss.
Clinical Findings—Hypermotile gastrointestinal sounds were noted on abdominal auscultation. An inflammatory leukogram, dehydration, prerenal azotemia, hyponatremia, hypochloremia, hyperproteinemia, hyperglobulinemia, hypomagnesemia, and high γ-glutamyl transpeptidase activity were identified. Transabdominal ultrasonography revealed distended loops of small intestine.
Treatment—IV fluid therapy and analgesic treatment were unsuccessful in the resolution of clinical signs. Exploratory laparotomy revealed an ileocecal intussusception involving the distal portion of the ileum. Distal ileal and cecal bypass were achieved via side-to-side anastomosis of the proximal portion of the ileum and spiral colon with a gastrointestinal anastomosis stapler. Ileal transection or occlusion was not performed. Postoperative complications were minimal, and the pig was clinically normal 15 months after surgery and required no special care or diet.
Clinical Relevance—Distal ileal and cecal bypass without ileal transection have not been described previously in Vietnamese pot-bellied pigs. Anastomosis of the proximal portion of the ileum to the spiral colon without major complications represents a novel, technically simple approach to bypass of the distal portion of the ileum and cecum.
A 61-kg (134.2-lb) 5-year-old castrated male Vietnamese pot-bellied pig (Sus scrofa) was evaluated at the veterinary teaching hospital because of diarrhea, vomiting, weight loss, and anorexia. The pig was reported to have had weight loss and frequent inappetence for the past 2 months with acute progression to anorexia, diarrhea, and vomiting during the previous 48 hours. Physical examination demonstrated lethargy, approximately 5% dehydration (skin tent and sunken eyes), increased gastrointestinal sounds on abdominal auscultation, left ocular discharge, and dry skin. In consideration of the diarrhea and additional clinical signs, initial diagnostic testing included a CBC, serum biochemical panel, quantitative fecal examination, bacteriologic culture of feces for Salmonella sp, abdominal ultrasonography, and abdominocentesis. Abnormal blood values included high total protein concentration (9.6 g/dL; reference range, 6.6 to 8.9 g/dL), hyperfibrinogenemia (700 mg/dL, reference range, 100 to 400 mg/dL), elevated band neutrophil count (7.11 × 103 neutrophils/μL, reference range, 0 × 103 neutrophils/μL to 0.19 × 103 neutrophils/μL), moderate neutrophil toxicity, high urea nitrogen concentration (67 mg/dL; reference range, 4.2 to 15.1 mg/dL), hyponatremia (123 mmol/L; reference range, 139 to 148 mmol/L), hypochloremia (83 mmol/dL; reference range, 106 to 113 mmol/dL), and increased γ-glutamyl transpeptidase activity (185 U/L; reference range, 14.5 to 56.2 U/L).1 No parasite ova were identified on quantitative fecal examination. Results of bacteriologic culture of feces were negative for Salmonella sp. Abdominal ultrasonography revealed dilated, hypomotile small intestine. The abdominocentesis was nondiagnostic because results were consistent with an inadvertent enterocentesis. Subsequently, the pig was restrained in dorsal recumbency with the forelimbs pulled in a caudal direction and the head straight. The area over the left jugular vein was clipped of hair and prepared in a sterile manner. A 10-MHz linear probe was used to identify the jugular vein.2 Following infusion of the skin with 1.5 mL of 2% lidocaine, a small stab incision was made in the skin to allow introduction of the catheter. By use of the Seldinger technique under ultrasound guidance, a 6F, 20-cm central venous cathetera was placed and the catheter and extension set were sutured to the skin with 2-0 nylon suture. Initial treatment included oxytetracycline (12 mg/kg [5.45 mg/lb], IV, q 24 h), flunixin meglumine (1.1 mg/kg [0.5 mg/lb], IV, q 24 h), and lactated Ringer's solution (2 mL/kg/h [0.91 mL/lb/h], IV). Twenty-four hours after admission, the pig was no longer azotemic. Hyponatremia and hypochloremia were unchanged. Forty-eight hours after admission, the pig was still anorexic and had diarrhea. Serum biochemical analysis revealed hypoproteinemia (4.3 g/dL; reference range, 6.6 to 8.9 g/dL) characterized by hypoalbuminemia (1.78 g/dL; reference range, 3.6 to 5.0 g/dL). Administration of lactated Ringer's solution was discontinued, and hydroxyethyl starch solution was given (16 mL/kg [7.3 mL/lb], IV). Administration of flunixin was discontinued, and administration of meloxicam (0.13 mg/kg [0.059 mg/lb], IV, q 24 h) was instituted.
Because of the lack of response to 48 hours of medical treatment, exploratory laparotomy was performed under general anesthesia. The pig was medicated with buprenorphine (0.01 mg/kg [0.0045 mg/lb], IV) 5 minutes prior to induction of anesthesia. Induction of anesthesia was achieved with 6 mg of propofol/kg (2.73 mg/lb) given as a slow bolus IV. The pig was orotracheally intubated and inhalation anesthesia was maintained with isoflurane in oxygen for the remainder of the surgery. The pig was positioned in dorsal recumbency, and a ventral midline celiotomy was performed. The prepuce was reflected off midline with a Backhaus towel clamp. The abdominal incision was centered at the umbilicus and extended 10 cm in total length cranially and caudally. Hemorrhage from the skin, subcutaneous tissues, and adipose tissue was controlled with electocautery. Upon entering the abdomen, multiple loops of fluid- and gas-distended jejunum with decreased motility were observed. The stomach was palpably empty of ingesta. The proximal ileum and distal jejunum were thickened, and the serosa appeared mildly corrugated. The distal ileum was not readily apparent. The cecum was devoid of ingesta, and a palpable intraluminal mass was identified. A diagnosis of ileocecal intussusception was confirmed after inspection through a 4-cm typhlotomy near the apex of the cecum. Because the cecum could not be exteriorized, it was isolated with laparotomy sponges prior to the typhlotomy. A short section of the most distal ileum was identified telescoped into the cecum. The inverted ileal mucosa was thickened but appeared pink with viable blood supply. The intussusception could not be manually reduced. The typhlotomy incision was closed with 2-0 polydioxanone suturesb in a simple continuous pattern, oversewn with 2-0 polydioxanone sutures in a Cushing pattern, and lavaged with sterile saline (0.9% NaCl) solution. Careful palpation of the remaining abdominal contents revealed no other abnormalities. Because of the thickened, corrugated appearance, a small (1.5-cm) full-thickness wedge biopsy was obtained from the antimesenteric border of the proximal ileum and submitted for Lawsonia PCR assay, results of which were negative. The biopsy site was oversewn with 3-0 polydioxanone sutures in a simple continuous pattern, followed by 3-0 polydioxanone sutures in a Cushing pattern and then lavaged with sterile saline solution. To perform the anastomosis, the proximal loop of spiral colon just oral to the initial centripetal turn was isolated with laparotomy sponges. The proximal ileum and distal jejunum lie just adjacent to this structure in the abdomen and were similarly isolated with laparotomy sponges. The spiral colon was largely devoid of ingesta. The fluid and gas in the small intestine were pushed orally by means of extramural pressure and maintained via manual restraint by an assistant using the thumb and forefinger to compress the lumen. The ileum and colon were placed side by side and aligned in an antipersistaltic position so that ingesta would flow into the colon in a direction opposite to normal flow, similar to the ileocolic anastomosis technique described in horses3 (Figure 1). Stay sutures between the proximal ileum and spiral colon were placed with 2-0 polydioxanone sutures in a cruciate pattern and used to elevate the anastomosis sites. Stab incisions (1.0 cm) were made through the antimesenteric border of the ileum and through the proximal loop of the spiral colon, close to the aboral stay sutures. The arms of a gastrointestinal anastomosis staplerc were passed through the stab incisions, and the anastomosis was created by activating the device 1 time. The stab incisions were closed in a simple continuous pattern with 2-0 polydioxanone sutures, followed by a Cushing pattern with 2-0 polydioxanone sutures. The anastomosis site was inspected and not reinforced. The abdomen was lavaged with 2 L of warm sterile saline solution, which was removed by suction prior to closure. The linea alba was closed with 1 polydioxanone suture in a continuous pattern. The adipose tissue was not sutured. The thin subcutaneous tissue was closed with 2-0 polydioxanone sutures in a continuous pattern. Surgical skin glue was used to oppose the skin edges. An iodophor-impregnated adhesive drape bandaged was placed over the incision and remained in place for 5 days. The pig recovered from anesthesia without complication.
Schematic of cecal bypass in a 61-kg (134.2-lb) 5-year-old castrated male Vietnamese pot-bellied pig (Sus scrofa), achieved via side-to-side anastomosis of the proximal portion of the ileum and spiral colon by means of a gastrointestinal anastomosis stapler.c
Citation: Journal of the American Veterinary Medical Association 241, 2; 10.2460/javma.241.2.237
Following surgery, the pig received oxytetracycline (12 mg/kg, IV, q 24 h) for 8 days during hospitalization, then amoxicillin (25 mg/kg [11.36 mg/lb], PO, q 12 h) for 7 days after discharge. Administration of meloxicam (0.13 mg/kg, IV, q 24 h) was continued for 4 days after surgery. Once the pig was awake and active, it was placed on a 1% lidocaine CRI (0.05 mg/kg/h [0.023 mg/lb], IV). However, within 3 hours after institution of the CRI, the pig was temporarily paretic in the hind end. This resolved within 20 minutes after discontinuing the lidocaine treatment. After several hours, the lidocaine CRI was started again (0.025 mg/kg/h [0.011 mg/lb], IV) and continued for 36 hours after surgery without adverse effects. It was intermittently stopped multiple times during this period to accommodate grazing and care. The pig was offered free-choice water, which it consumed in appropriate amounts within 12 hours after surgery. Eighteen hours after surgery, the pig was offered and readily consumed apple juice. At 24 hours after surgery, the pig was offered canned, wet dog foode and allowed to graze intermittently on fresh grass. Its food intake was gradually increased for several days until it was grazing for up to 2 h/d and eating maintenance rations of moistened commercial pig feed. Five days after surgery, the pig had not yet defecated. Ducosate sodium was added to its feed, and the pig passed normal feces 6 days after surgery. It was discharged to the owner 6 days after surgery on a normal diet. At 15 months after surgery, the owner reported via telephone conversation that the pig had gained weight (normal weight) and was eating a diet of commercial pig feed and grazing. The skin incision healed normally, and no long-term complications were reported. The owner reported excellent satisfaction with the outcome.
Discussion
Ileocecal intussusceptions have been anecdotally reported as a diagnosis in Vietnamese pot-bellied pigs, but have not been documented in the peer-reviewed literature. The pig of the present report had negative results for fecal egg count, bacteriologic culture of feces for Salmonella spp, and Lawsonia PCR assay. The cause of this patient's intussusception is not known. In 1 study4 of human patients, approximately 88% of cases were idiopathic. A report5 of 51 calves with intussusceptions included 40 cases of intussusceptions that occurred during the course of diarrheal disease, similar to the case described in the present report, although it is unknown whether the diarrhea was the cause or effect of the intussusception. The clinical signs observed in the pig of the present report included weight loss, anorexia, diarrhea, vomiting, and lethargy. Results of blood tests were supportive of dehydration and potential obstruction of the proximal portion of the gastrointestinal tract (hyponatremia and hypochloremia).6 Ultrasonography was suggestive of small intestinal motility dysfunction or obstructive disease but did not identify the specific lesion. The chronicity of clinical signs seen in the pig of the present report (2-month duration of weight loss and inappetence) is similar to that described in reports7,8 of horses with cecocolic intussusceptions.
Anastamosis of the ileum to the proximal spiral colon without transection or occlusion of the ileum in pot-bellied pigs has not been reported in the literature. A single case report9 exists describing an ileocolic anastomosis involving use of the distal descending colon with transection and removal of the cecum and most of the spiral colon. There are reported experimental studies10,11 of removal of the entire large intestines in pigs. One key difference in the patient of the present report is the lack of transection and removal of the affected intestine. This was feasible in this pig because of the visible absence of ischemia in the intussusceptum. This method is a modification of a technique used in previous studies3,12 of horses. It is our opinion that the procedure was overall technically easy to perform, with short surgical time and minimal abdominal contamination. It is also technically possible to perform a jejunocolic anastomosis in the same manner if the proximal ileum is not available. Potential risks associated with this procedure include strangulation of the intussusceptum and subsequent necrosis, leakage, and peritonitis as well as complications associated with anastomosis of 2 dissimilar portions of bowel, such as flow of colonic ingesta orally into the small intestine. Results of a previous study13 in horses suggest that inverted portions of bowel may eventually slough or atrophy. These potential complications influenced the choice of prolonged antimicrobial use in the patient of the present report.
It is difficult to choose drugs for use in pot-bellied pigs because they are considered food animals by the US FDA and fall under guidelines of the AMDUCA. There is no licensed drug for signs of abdominal pain in pigs; however, meloxicam (2%)e is an NSAID licensed for the treatment of metritis, mastitis, agalactiae syndrome, and lameness in pigs. Clinician preference just prior to surgery was to switch from flunixin meglumine to meloxicam. Lidocaine CRI has been reported in the postoperative management of ileus and signs of pain in other species.14 The pig of the present report had thickened small intestine oral to the anastomosis, and lidocaine was used in an attempt to decrease inflammation and signs of pain related to the affected intestine. The use of CRIs of lidocaine in pot-bellied pigs has not been studied or reported, to our knowledge. The initial choice of the antimicrobial oxytetracycline carries some risk for nephrotoxicity, especially with the prerenal azotemia.15 In this patient, IV fluids were used to hydrate the animal prior to administration of oxytetracycline and to decrease the risk of nephrotoxicity. Other antimicrobials, such as ceftiofur, may have provided adequate coverage with less risk of nephrotoxicity.
The patient of the present report was free of complications and in good body condition 15 months after the surgery, suggesting a lack of adverse effects from the procedure. Although ileocecal intussusceptions appear to be a rare occurrence in pot-bellied pigs, the information gained from this successful procedure may help to successfully treat any condition requiring bypass of the ileum or cecum in pot-bellied pigs.
ABBREVIATION
| CRI | Constant rate infusion |
Central venous catheter, Cook Medical, Bloomington, Ind.
Polydioxanone, Ethicon, Allentown, NJ.
GIA 50 Premium Stapler, United States Surgical Corp, Norwalk, Conn.
Ioban, 3M Co, Saint Paul, Minn.
Science Diet A/D, Hill's Pet Food, Topeka, Kan.
Metacam, Boehringer-Ingelheim, Burlington, ON, Canada.
References
1. Brockus CW, Mahaffey EA, Bush SE, et al. Hematologic and serum biochemical reference intervals for Vietnamese potbellied pigs (Sus scrofa). Comp Clin Pathol 2005; 13:162–165.
2. Brederlau J, Muellenbach R, Kredel M, et al. Comparison of arterial and central venous cannulations using ultrasound guidance in pigs. Vet Anesth 2008; 35:161–165.
3. Lores M, Ortenburger AI. Use of cecal bypass via side-to-side ileocolic anastomosis without ileal transection for treatment of cecocolic intussusception in three horses. J Am Vet Med Assoc 2008; 232:574–577.
4. Pang LC. Intussusception revisited: clinicopathologic analysis of 261 cases, with emphasis on pathogenesis. South Med J 1989; 82:215–228.
5. Doll K, Klee W, Dirksen G. Caecal intussusceptions in calves [in German]. Tierarztl Prax Ausg G Grosstiere Nutztiere 1998; 26:247–253.
6. Constable PD, St. Jean G, Hull BL, et al. Intussusception in cattle: 336 cases 1964–1993. J Am Vet Med Assoc 1997; 210:531–536.
7. Martin BB Jr, Freeman DE, Ross MW, et al. Cecocolic and cecocecal intussusceptions in horses: 30 cases (1976–1996). J Am Vet Med Assoc 1999; 214:80–84.
8. Gaughan EM, Hackett RP. Cecocolic intussusception in horses: 11 cases (1979–1989). J Am Vet Med Assoc 1990; 197:1373–1375.
9. Bassett JR, Mann FA, Constantinescu GM, et al. Subtotal colectomy and ileocolonic anastomosis in a Vietnamese potbellied pig with idiopathic megacolon. J Am Vet Med Assoc 1999; 215:1640–1643.
10. Wilkinson AW, McCance RA. The subsequent effects of removing the large intestine from newborn pigs. Proc Nutr Soc 1971; 30:26A–27A.
11. Redlich J, Souffrant WB, Laplace JP, et al. Morphometry of the small intestine in pigs with ileo-rectal anastomosis. Can J Vet Res 1997; 61:21–27.
12. Bell RJW, Textor JA. Caecal intussusceptions in horses: a New Zealand perspective. Aust Vet J 2010; 88:272–276.
13. Boussauw BH, Domingo R, Wilderjans H, et al. Treatment of irreducible caecocolic intussusceptions in horses by jejuno(ileo) colostomy. Vet Rec 2001; 149:16–18.
14. Cook VL, Jones Schultz J, McDowell MR, et al. Anti-inflammatory effects of intravenously administered lidocaine hydrochloride on ischemia-injured jejunum in horses. Am J Vet Res 2009; 70:1259–1268.
15. Vaala WE, Ehnen SJ, Divers TJ. Acute renal failure associated with administration of excessive amounts of tetracycline in a cow. J Am Vet Med Assoc 1987; 191:1601–1603.
