Donald L. Neiffer

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 α1 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.

REVIEW OF 23 CASES OF POSTINTUBATION TRACHEAL OBSTRUCTIONS IN BIRDS

Although recognized as a potential complication after endotracheal intubation in birds, the complication rate of postintubation tracheal obstruction in this taxon is unknown. Twenty-three cases of postintubation obstruction in birds from two institutions are reported. Clinical signs were noted an average of 16.6 days postintubation and consisted primarily of indications of acute respiratory distress. Diagnosis was confirmed via tracheoscopy or radiology. Five birds died before treatment could be initiated. Medical treatment alone was successful in three birds that had mild changes consisting primarily of a luminal mucoid plug that could be manually removed without tracheal surgery but was unsuccessful in an additional six birds. Tracheal resection and anastamosis was successful in four birds and unsuccessful in five birds. Overall mortality was 70%. Postintubation tracheal obstruction in birds appears to be more common in zoo practice than is suggested by the literature, as a total of 1.8% (1.2-2.7%, 95% confidence interval) of intubations or 3.5% (2.3-5.3%, 95% confidence interval) of individual animals intubated in these institutions resulted in this complication. Multiple cases were found in Ciconiiformes (n = 4), Columbiformes (n = 4), Gruiformes (n = 4), Anseriformes (n = 3), Galliformes (n = 3), and Passeriformes (n = 2). No cases were found in Coraciiforms, Falconiforms, or Psittaciformes despite many (>40) recorded intubations. The specific cause of these lesions is unclear, but some type of tracheal mucosa trauma or irritation is suggested by histologic findings. Prevention may include selective intubation, use of a laryngeal mask airway in place of intubation, careful placement of an endotracheal tube, minimal movement of the head and neck after placement, humidification of anesthetic gases, and gentle positive-pressure ventilation.

Changes in Serum Calcium, Phosphorus, and Magnesium Levels in Captive Ruminants Affected By Diet Manipulation

Abstract A combination of low serum calcium (Ca), high serum phosphorus (P), and low serum magnesium (Mg) has been observed in individual captive ruminants, primarily affecting kudu (Tragelaphus strepsiceros), eland (Taurotragus oryx), nyala (Tragelaphus angasii), bongo (Tragelaphus eurycerus), and giraffe (Giraffa camelopardalis). These mineral abnormalities have been associated with chronic laminitis, acute tetany, seizures, and death. Underlying rumen disease secondary to feeding highly fermentable carbohydrates was suspected to be contributing to the mineral deficiencies, and diet changes that decreased the amount of starch fed were implemented in 2003. Serum chemistry values from before and after the diet change were compared. The most notable improvement after the diet change was a decrease in mean serum P. Statistically significant decreases in mean serum P were observed for the kudu (102.1–66.4 ppm), eland (73.3–58.4 ppm), and bongo (92.1–64.2 ppm; P < 0.05). Although not statistically significant, mean serum P levels also decreased for nyala (99.3–86.8 ppm) and giraffe (82.6–68.7 ppm). Significant increases in mean serum Mg were also observed for kudu (15.9–17.9 ppm) and eland (17.1–19.7 ppm). A trend toward increased serum Mg was also observed in nyala, bongo, and giraffe after the diet change. No significant changes in mean serum Ca were observed in any of the five species evaluated, and Ca was within normal ranges for domestic ruminants. The mean Ca:P ratio increased to greater than one in every species after the diet change, with kudu, eland, and bongo showing a statistically significant change. The results of this study indicate that the diet change had a generally positive effect on serum P and Mg levels.

MANAGEMENT OF REACTIVE ARTHRITIS IN A JUVENILE GORILLA (GORILLA GORILLA GORILLA) WITH LONG-TERM SULFASALAZINE THERAPY

Abstract 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 gorillas 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.

Exploratory rigid laparoscopy in an African elephant (Loxodonta africana).

Abstract:  In March 2009, a 25-yr-old captive female African elephant (Loxodonta africana) underwent an exploratory laparoscopy after several weeks of diarrhea, submandibular and ventral edema, and swelling on medial and lateral aspects of all feet. Although there have been recent advances in laparoscopic vasectomies in free-ranging African elephants in South Africa utilizing specially designed rigid laparoscopes and insufflation devices, this was the first attempt at using these same techniques for an exploratory purpose. The elephant was sedated in a static restraint chute and remained standing for the duration of the procedure. Laparoscopy provided visibility of the dorsal abdomen, enabled collection of reproductive tract biopsies and peritoneal fluid samples, and allowed for instillation of antibiotics and crystalloid fluids directly into the abdominal cavity. Abdominal exploration, collection of tissue samples, and local therapy is possible via standing laparoscopy in megavertebrates.

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

Abstract 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.

Endolymphatic Sac Carcinoma In Situ in a Tokay Gecko (Gekko gecko)

Abstract An 11-year-old female tokay gecko (Gekko gecko) was presented for bilateral asymmetric swellings of the cervical region. Baseline hematologic and plasma biochemical analyses demonstrated anemia, hypercalcemia, hyperphosphatemia, and hypoalbuminemia. Whole-body radiographs revealed a mass effect and irregular mineralization in the region of the left endolymphatic sac. Fine needle aspiration of this region revealed many elongated calcium-based crystals with pointed ends, histiocytic inflammation, and clusters of epithelial cells, consistent with hyperplasia or neoplasia of the epithelium of the endolymphatic sac. The crystals were shown to be calcium carbonate by infrared crystallography. Given the advanced state of disease and inability to completely excise the mass due to the intimate association between the meninges and endolymphatic sac, the gecko was euthanized. Gross necropsy and histopathologic evaluation revealed carcinoma in situ of the left endolymphatic sac. To our knowledge, this is the first report of neoplasia of the endolymphatic sac in a reptile.

Pachydermoperiostosis-like Disease in Captive Red Ruffed Lemurs (varecia variegatus rubra)

Background: Pachydermatoperiostosis, a rare form of hypertrophic osteoarthropathy, is of unknown etiology and previously thought limited to humans. Secondary hypertrophic osteoarthropathy is a known problem that transcends mammalian phylogeny, but has not previously been recognized in prosimians. The only periosteal reaction previously reported in prosimians is related to renal disease. Methods: Clinical and radiological assessment was performed on lemurs with hypertrophic osteoarthropathy. Results: Three related red ruffed lemurs ( Varecia variegates rubra ) had diaphyseal periosteal reaction classic for hypertrophic osteoarthropathy. Workup was negative for known underlying causes and for the secondary hyperparathyroidism which produces bone alterations in black Eulemur macao, black and white Varecia variegatatus varigatus and ringtail Lemur catta lemurs. Conclusions: Recognition of facial coarsening allows identification of the primary form of hypertrophic osteoarthropathy. This is the first recognition of the phenomenon in the order primates, exclusive of humans, and represents a new model for this rare diseas

CALCINOSIS CIRCUMSCRIPTA IN A COHORT OF RELATED JUVENILE AFRICAN LIONS (PANTHERA LEO)

Abstract Three juvenile, genetically related African lions (Panthera leo) were evaluated for discrete dome-shaped subcutaneous masses present over the proximal lateral metatarsal-tarsal area. The lesions measured 3–8 cm in diameter, were fluctuant to firm, nonulcerated, and attached to underlying structures. On radiographic evaluation, the lesions were characterized by well-circumscribed punctate mineralizations in the soft tissue surrounded by soft tissue swelling without evidence of adjacent bony involvement. On cut surface, the lesions were made of numerous loculi containing 2–5-mm round-to-ovoid, white-to-gray, firm structures interspersed with fibrous tissue and pockets of serosanguinous fluid. Hematology, serum biochemistry, serum thyroid screening (including total thyroxine, total triiodothyronine, free thyroxine, and free triiodothyronine), and serum vitamin D panels (including parathyroid hormone, ionized calcium, and 25-hydroxyvitamin D) were unremarkable. Histopathologic evaluation of the lesions was consistent with calcinosis circumscripta with fibroplasia, chronic inflammation, and seroma formation. An additional two genetically related lions were considered suspect for calcinosis circumscripta based on presentation, exam findings, and similarity to the confirmed cases. All masses self-regressed and were not associated with additional clinical signs other than initial lameness in two cases.