Gorillas with spondyloarthropathies express an MHC class I molecule with only limited sequence similarity to HLA-B27 that binds peptides with arginine at P2.

The human MHC class I gene, HLA-B27, is a strong risk factor for susceptibility to a group of disorders termed spondyloarthropathies (SpAs). HLA-B27-transgenic rodents develop SpAs, implicating HLA-B27 in the etiology of these disorders. Several nonhuman primates, including gorillas, develop signs of SpAs indistinguishable from clinical signs of humans with SpAs. To determine whether SpAs in gorillas have a similar HLA-B27-related etiology, we analyzed the MHC class I molecules expressed in four affected gorillas. Gogo-B01, isolated from three of the animals, has only limited similarity to HLA-B27 at the end of the alpha1 domain. It differs by several residues in the B pocket, including differences at positions 45 and 67. However, the molecular model of Gogo-B*0101 is consistent with a requirement for positively charged residues at the second amino acid of peptides bound by the MHC class I molecule. Indeed, the peptide binding motif and sequence of individual ligands eluted from Gogo-B*0101 demonstrate that, like HLA-B27, this gorilla MHC class I molecule binds peptides with arginine at the second amino acid position of peptides bound by the MHC class I molecule. Furthermore, live cell binding assays show that Gogo-B*0101 can bind HLA-B27 ligands. Therefore, although most gorillas that develop SpAs express an MHC class I molecule with striking differences to HLA-B27, this molecule binds peptides similar to those bound by HLA-B27.

Leptospira infection in two black rhinoceroses (Diceros bicornis michaeli).

Two black rhinoceroses (Diceros bicornis michaeli) developed clinical leptospirosis without hemolytic crises. The first rhinoceros presented with peracute depression, anorexia, rear leg trembling, dysuria, glucosuria, gastrointestinal discomfort, and decreased fecal output and died within 12 hr. Necropsy and histopathology revealed lesions within multiple organs. Leptospirosis was diagnosed postmortem based on positive fluorescent antibody staining of liver. The second rhinoceros presented 2 mo later with similar signs. It survived with treatment and was diagnosed with leptospirosis based on serology using microscopic agglutination testing and detection of urinary antigen using a fluorescent antibody technique. Leptospira kirschneri serovar grippotyphosa was postulated as the etiologic agent, with transmission probably occurring through wallow contamination by wild raccoons (Procyon lotor).

Clostridium perfringens enterotoxicosis in two Amur leopards (Panthera pardus orientalis).

Two 6-yr-old male sibling Amur leopards (Panthera pardus orientalis) housed together at the Pittsburgh Zoo presented for acute onset of diarrhea with no changes in appetite or behavior. Heat-fixed modified Wright-stained and Gram-stained fecal smears revealed a mixed bacterial population with a large number of gram-positive Clostridium perfringens-like spores (>20 per high-power oil immersion field). In addition, C. perfringens enterotoxin was isolated from one leopard at 1:256, confirming the presence of C. perfringens enterotoxicosis. Treatment with oral metronidazole, tylosin tartrate, and psyllium fiber was prescribed, with return of more normal stool by the third day of treatment. Fecal consistency steadily improved and was considered normal by the time all prescribed treatments were complete. Diarrhea has not recurred. Partially thawed meat in the leopards' diet may have precipitated the production of an endogenous clostridial enterotoxicosis by disrupting digestive tract flora with resultant clostridial overgrowth and sporulation.

Interstitial cell tumor in a black-and-white ruffed lemur (Varecia variegatus variegatus).

A 14.5-yr-old, male black-and-white ruffed lemur (Varecia variegatus variegatus) presented for acute enlargement of the left testicle and hemiscrotum. Physical examination also revealed poor pelage quality with short guard hairs, sparse undercoat, and areas of alopecia. Increased aggression was also reported. A unilateral, open orchiectomy was performed, with the left testicle, epidydymis, associated vaginal tunic, and attached spermatic cord removed. Microscopic evaluation was consistent with an interstitial cell tumor, with many morphologic features similar to this neoplasm in people. No overt histopathologic criteria of malignancy were present. Following orchiectomy, gradual improvement in pelage quality was noted and was considered almost normal by 5 mo postoperative. In contrast with the aggressive preoperative behavior, the lemur was extremely submissive for 3 mo following the surgery. Gradual return to normal behavior and social status occurred over the next 2 mo. Multiple follow-up examinations and radiographs revealed no evidence of metastasis, and biopsy of the remaining testicle 4 mo later revealed no evidence of neoplasia. Serial measurements of testosterone and estradiol revealed levels within the range of those for other ruffed lemurs, as were repeated measurements taken of the remaining testicle. At 19 mo postoperative, the lemur had a coat quality considered nearly normal and maintained its historical social position in the lemur group without abnormal aggressive behavior.

Management of reactive arthritis in a juvenile gorilla (Gorilla gorilla gorilla) with long-term sulfasalazine therapy.

A juvenile western lowland gorilla (Gorilla gorilla gorilla) experienced recurrent fever, lethargy, diarrhea, and/or arthritis starting at age 6 mo. During an episode at age 15 mo, Shigella sp. was isolated from diarrheic feces. At age 41 mo, reactive arthritis was diagnosed. In addition, the gorilla's growth was retarded. All arthritic attacks were managed symptomatically prior to age 4 yr, at which time a severe episode precipitated the implementation of therapy with sulfasalazine, an arthritis suppressive medication. Examination 27 mo later revealed cessation of progressive joint pathology although the animal exhibited decreased range of motion in most joints. The gorilla has been on sulfasalazine therapy for 4 yr without lameness. Growth has resumed, and there has been no radiographic evidence of progressive joint degeneration. Immunogenetic analysis of whole blood obtained at age 68 mo identified the gorilla major histocompatibility class I allele, Gogo-B*0101, which has limited nucleotide sequence similarity to HLA-B27, an allele associated with postinfection reactive arthritis in humans. Sulfasalazine therapy effectively managed reactive arthritis in this gorilla and should be considered for similarly frequently affected animals. Juvenile gorillas, in populations with a history of clinical shigellosis and/or postdiarrhea arthritis, may benefit from prophylactic sulfasalazine therapy after episodes of bacterial enterocolitis. Sulfasalazine therapy should be considered in all gorillas, juvenile and adult, experiencing confirmed Shigella sp.-associated enterocolitis.

Use of pyloroplasty (Y-U) to treat presumed delayed gastric emptying in a cheetah (Acinonyx jubatus).

A 4-yr-old cheetah (Acinonyx jubatus) with a 2-yr history of chronic intermittent vomiting and spiral bacteria-associated gastritis presented with dramatically increased vomiting frequency and marked intermittent abdominal distention. Physical examination revealed loss of muscle mass and poor fur coat quality. Contrast radiography was consistent with delayed gastric emptying due to presumed gastric outlet obstruction. Both Y-U pyloroplasty and incisional gastropexy were performed, and no subsequent vomiting has been observed for 3 yr with the exception of three episodes during the immediate postoperative period. The cause of delayed gastric emptying was not determined, although a gastric motility disorder associated with gastric bacterial infection and elevated gastrin levels was suspected.

Cecal inversion and subsequent colocolic intussusception in a red wolf (Canis rufus gregoryi).

A 2-yr-old female red wolf (Canis rufus gregoryi) presented with weight loss and diarrhea. Abnormal clinical pathology included low serum calcium, sodium, chloride, globulin, and albumin levels. Differential diagnosis included infectious enteritis, intestinal parasitism, inflammatory bowel disease, hepatic or renal disease, and malnutrition. The wolf was treated empirically, but did not improve. A second examination revealed persistent poor musculature and stool quality. Abdominal palpation revealed a firm mass; contrast radiography confirmed an intussusception. Exploratory laparotomy revealed a colocolic intussusception involving the cecum. Following reduction of the colocolic intussusception, cecal inversion (cecocolic intussusception) was identified. Because the cecal inversion could not be reduced, typhlectomy was performed through a colotomy incision. Bacterial culture of peritoneal fluid yielded two strains of Escherichia coli. Postoperatively, the wolf was placed on antibiotics and a soft diet. The diet was gradually returned to its normal formulation and the wolf progressively gained weight. Physical examination 7.5 mo following initial presentation revealed normal body weight and condition. To our knowledge, this is the first recorded incidence of cecal inversion with concurrent colocolic intussusception.