Abstract
The okapi is one of only two species in the family of Giraffidae.4,7 Unlike giraffe which inhabit a wide area on the African continent, okapi are confined to the dense tropical rainforests of the Democratic Republic of the Congo (formerly Zaire).4 Like the giraffe, okapi are browsers that select high-protein forages and utilize a ruminant gastrointestinal tract to process and absorb nutrients.7 The proximal portion of the ruminant gastrointestinal tract is composed of a compartmentalized forestomach, a glandular abomasum and several associated orifices through which ingesta flows via intermittent, synchronized contractions. Although over 190 okapi have been bred in captivity and much has been learned about reproduction in this species, there is little published material concerning invasive surgical procedures required to correct gastrointestinal abnormalities.9 Typically, a diagnosis of ruminal or abomasal impaction in domestic ruminants such as cattle carries an unfavorable prognosis.1,2,5,8,10 Impaction of the rumen and abomasum are described as causes of death in okapi, but no accounts of successful correction, surgical technique, postoperative care, and the ability of this species to tolerate invasive surgical manipulation have been reported.7,9
In November 1998, a 22-month-old male okapi which was born at the Denver Zoo was observed consuming a keeper’s work glove. The work glove was composed of woven cotton fiber and a rubberized, waterproof coating. Unfortunately, the keeper was unable to retrieve the glove before it was swallowed. Over the ensuing 72 hours, the okapi became depressed as well as anorectic and demonstrated signs of abdominal discomfort. No fecal output was detected, and the animal eventually became reluctant to rise from sternal recumbency. The okapi was initially sedated with 30 mg of xylazine (Xyla-Ject, Phoenix Pharmaceuticals, Inc., St. Joseph, MO) intramuscularly via a pole syringe. Twenty minutes later, 0.7 mg of carfentanil citrate (Wildlife Laboratories, Fort Collins, CO, USA) was administered intramuscularly via a pole syringe to achieve immobilization. As reported by Bush with regard to giraffe, regurgitation in the okapi also occurs within seconds of immobilization.3 Despite being maintained in sternal recumbency, this individual regurgitated enumerable times, producing gallons of rumen contents before, during, and after transport to the hospital. Decompression with a stomach tube and intubation with a 16-mm endotracheal tube facilitated safe rotation of the okapi into left lateral recumbency. Although a standard rumenotomy in domestic species is generally approached from the left flank, the necessity of exploring all of the chambers of the proximal gastrointestinal tract required an approach through the right flank.1,5,6,11 Initially the caudodorsal aspect of the rumen was exteriorized through an approximately 37-cm curvilinear incision caudal to the last rib. The rumen contents were predominantly liquid with very little fibrous material, and complete evacuation facilitated further exploration. A portion of the glove’s cotton lining was retrieved from the ruminoreticular orifice. The material appeared to be of adequate size to cause blockage of the orifice. The rumenotomy incision was closed with two inverting suture patterns. An abomasotomy was also performed in order to complete a thorough digital evaluation of the remaining compartments of the forestomach. Evacuation of the abomasum’s firmer fibrous content revealed a diffusely erythematous mucosal lining. Several smaller pieces of glove material were retrieved; however, the amount of material recovered could not account for the entire glove. Although evacuation of gastric contents enabled adequate exposure and visualization, contamination of the peritoneal cavity was very difficult to prevent. Contamination was minimized by packing the margins of the incision with sterile laparotomy sponges and vigorously lavaging the exposed serosal surfaces. The abomasum was also closed with two inverting suture patterns. The body wall was closed in five layers using various sizes and appositional patterns of absorbable suture material. One gram of ceftazidime (Fortaz, Glaxo Pharmaceuticals, Research Triangle Park, NC) was administered intravenously, and 12,000,000 IU of penicillin G procaine and penicillin G benzathine (Aspen Veterinary Resources, Ltd., Kansas City, MO) was administered subcutaneously perioperatively. In addition, 400 g of flunixin meglumine (Banamine, Schering-Plough Animal Health Corp., Kenilworth, NJ) was divided intravenously as well as subcutaneously for pain relief.
In this case, postoperative concerns included incomplete removal of the foreign material, aspiration pneumonia, peritonitis, gastrointestinal atony, elimination of essential gastrointestinal microflora, and dehiscence of the suture line. Within 12 hours of anesthetic recovery, the okapi appeared alert and reactive. Postoperative care consisted of gradual reintroduction to water, forages, and produce over 72 hours following surgery. The okapi began defecating normally 6 days after the procedure. Produce was supplemented with maternal fecal material in an attempt to repopulate the gastrointestinal tract with essential microflora. Despite the absence of postoperative antibiotic therapy and gastrointestinal motility enhancers, the only complications noted throughout recovery were compulsive licking along the suture line and several areas of pressure necrosis on bony prominences as well as the left side of the animal’s neck. Based on this case, it appears that okapi are able to tolerate surgical manipulation of the gastrointestinal tract for the purpose of foreign body removal; however, careful consideration of okapi physiology and behavior is essential for success.
Literature Cited
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