Abstract

A 2-yr-old, 101-kg, intact male Siberian tiger (Panthera tigris) presented to the University of Florida, Veterinary Medical Teaching Hospital (VMTH) with constipation and anorexia of 5 days duration. When the animal was 3-4 mo of age, he had bilateral cranial sacroiliac subluxations and a fractured left iliac shaft that had been allowed to heal without surgical intervention. The last meal the animal was known to have consumed was a lamb, a novel food source for this tiger, 5 days prior to presentation. The animal appeared lethargic, dehydrated, and when attempting to defecate it strained and passed small amounts of mucus and liquid feces, but no blood. A complete blood count and serum biochemistry profile indicated an elevated hematocrit and total protein, which were consistent with dehydration. Three liters of lactated Ringer's solution were administered i.v. over a 2-hr period. The next day, the tiger was anesthetized for examination and additional diagnostic tests.

On radiographic examination the descending colon was distended and contained dense, compacted fecal material with multiple bone fragments. The pelvis showed healed, bilateral cranial sacroiliac subluxations and a healed left iliac shaft fracture which resulted in moderate narrowing of the pelvic canal. The radiographic interpretation was constipation and healed pelvic fractures with pelvic canal stenosis. An enema was performed to attempt to relieve the impaction, but was unrewarding. The owner was presented with the options for therapy for the animal, including medical and surgical treatment. Due to the difficulty and intensity required in managing this aggressive animal medically, the owner requested surgical intervention in the form of a sub-total colectomy.

The tiger was placed in dorsal recumbency for a ventral midline abdominal incision was from the umbilicus to the pubis. The terminal colon was impacted with about 15 cm of hard, noncompressible material. Orad to this obstruction the colon was distended to the level of the cecum with fluid. The diameter of the colon was approximately 8 cm. The affected bowel appeared flaccid initially but contractions were noted following manipulation of the intestine. The appropriate colic and caudal mesenteric vessels were ligated using medium hemostatic clips (Hemoclips®, Edward Weck & Co. Inc., Research Triangle Park, NC 27709 USA). Anastomosis of the distal ileum and rectum was accomplished using 2-0 polydioxanone suture in a simple interrupted pattern. Omentum was tacked to the site of the anastomosis using 3-0 polydioxanone suture. The mesocolon was sutured using 3-0 polydioxanone suture in a simple continuous pattern. The abdominal cavity was irrigated with 0.05% chlorhexidine solution in saline. Closure was routine.

Ampicillin (Polyflex®, Fort Dodge Animal Health, Fort Dodge, IA 50501 USA) at a dose of 25 mg/kg, i.m. was given approximately 12 hr before surgery and continued every 8 hr for 12 days. Amikacin sulfate at a dose of 5 mg/kg was administered intraoperatively and every 8 hr for 5 days. Analgesia was provided using one dose of 15 µ/kg buprenorphine hydrochloride, i.m., approximately 1 hr after induction of anesthesia and continued every 8 hr at a dose of 5 µ/kg, i.m., for a total of three doses. The day after surgery, the tiger's feces were considerably more watery as expected. His appetite had returned and he was drinking water normally. He was discharged from the hospital 5 days after surgery. Four months later, the tiger was back to normal activity and had a good appetite. He was eating a diet of turkey, beef, and venison. The consistency of his stools was soft and the owner had noticed no difficulty in defecation since surgery.

Constipation in large felids can be caused by changes in diet, dehydration, the presence of foreign material including hair in the stool, impacted anal sacs or a malformed pelvic canal.^1,3,4 Although captive wildlife species present their own challenges to therapeutic management, this case report highlights that treatment options used in domestic species may be applied to nondomestic species such as the tiger. When an underlying cause can be identified, correction of the primary problem may alleviate the condition.¹ Medical management of these cases in domestic species include warm water enemas, laxatives, and soluble fiber dietary supplements.^1-3,5 Limitations in medical management of large exotic species are related to the amount of restraint necessary to administer medication and the amount of stress that is placed on the patient with each capture. In cases that are chronic or difficult to manage, a subtotal colectomy is the recommended treatment.¹ Since the colon is a major site for water resorption, removal of this organ would make the feces more watery, allowing the fecal material to pass through the stenotic pelvic canal more easily. Subtotal colectomy may be the most rewarding treatment option for these difficult to manage species.

References

1.  Bright RM. 1998. Subtotal colectomy in the cat. In: Current Techniques in Small Animal Surgery, 4th ed. M.J. Bojrab (ed.). Williams and Wilkins, Baltimore, Maryland, Pp. 272-276.

2.  Denovo RC. 1995. Constipation, tenesmus, dyschezia, and fecal incontinence. In: Textbook of Veterinary Internal Medicine, 4th ed. S.J. Ettinger, and E.C. Feldman (eds.). W.B. Saunders Company, Philadelphia, Pennsylvania, Pp. 115-122.

3.  Murdoch D. 1996. Large intestinal disease. In: BSAVA Manual of Canine and Feline Gastroenterology, 1st ed. D. Thomas, J.W. Simpson, and E.J. Hall (eds.). Iowa State University Press, Ames, Iowa, Pp. 151-169.

4.  Wallach JD, WJ Boever. 1983. Diseases of Exotic Animals: Medical and Surgical Management. W.B. Saunders Company, Philadelphia, Pennsylvania, Pp. 345-403.

5.  Washabau RJ, AH Hasler. 1997. Constipation, obstipation, and megacolon. In: Consultations in Feline Internal Medicine, 3rd ed. J.R. August (ed.). W.B. Saunders Company, Philadelphia, Pennsylvania, Pp. 104-112.