A RETROSPECTIVE EVALUATION OF MORBIDITY AND MORTALITY IN ASSOCIATION WITH INFESTATION BY THE MITE STERNOSTOMA TRACHEACOLUM IN AN AVIARY-HOUSED POPULATION OF GOULDIAN FINCHES (CHLOEBIA GOULDIAE).

The Rhynonyssid mesostigmatic mite, Sternostoma tracheacolum, is a well-documented endoparasitic hematophagous arthropod of the respiratory tracts of multiple avian species, particularly Estrildid finches and canaries. In this retrospective study, 175 medical and 278 pathology records for the Gouldian finch (Chloebia gouldiae) population (N = 377) at the San Diego Zoo between 2013 and 2021 were analyzed to evaluate the effectiveness of ivermectin-based prophylaxis. A multivariable negative binomial regression model was constructed to evaluate the population effects of monthly treatments on morbidity or mortality associated with respiratory mites. While controlling for other factors in the model, the prophylactic treatment did not significantly reduce the monthly rate of mite-associated morbidity or mortality (IRR = 1.017, 95% CI: 0.997-1.036, P = 0.0759); however, low proportions of the population were prophylactically treated over time. Different factors were significant when separately evaluating adjusted associations with respiratory morbidity and mortality. The findings suggest increased rates of respiratory morbidity for each successive year of the study period (IRR = 1.180, 95% CI: 1.046-1.342, P = 0.0090) and increased rates of mite-associated mortality occurring annually between May and October (IRR = 1.697, 95% CI: 1.034-2.855, P = 0.0404) compared to the wet winter season. Our findings highlight the need to continually evaluate and optimize treatment regimens in zoological collections. Further investigations into this host-parasite relationship and potential treatments and preventive therapies are warranted.

CLINICAL AND PATHOLOGIC FINDINGS IN IGUANIDS WITH SODIUM URATE CHOLELITHIASIS.

Four green iguanas (Iguana iguana) and one blue iguana (Cyclura lewisi) from five facilities were diagnosed with sodium urate cholelithiasis. One case was diagnosed antemortem via ultrasonography, and the iguana underwent a choledochotomy for treatment. The other four cases were identified at necropsy. Pathologic hepatic and biliary changes were present in four of the five cases at necropsy. Histologically, four iguanas had hepatic fibrosis, three had bile duct hyperplasia, and one had cholangiohepatitis and pancreaticocholedochitis. Two iguanas had pathologic renal changes. This is the first report of sodium urate cholelithiasis in reptiles. This case series highlights the potential significant clinical disease caused by sodium urate cholelithiasis and the importance of biliary system evaluation. Further investigation is recommended to explore the pathogenesis of reptilian sodium urate cholelith formation.

RETROSPECTIVE REVIEW OF UROLITHIASIS-RELATED MORBIDITY AND MORTALITY IN ASIAN COLOBINE MONKEYS.

Obstructive and incidental urolithiasis cases were evaluated in 5 Asian colobine monkey species (n= 21 individuals) that included 12 silvery langurs (Trachypithecus cristatus), 6 spectacled langurs (Trachypithecus obscurus), 1 Javan langur (Trachypithecus auratus auratus), 1 François' langur (Trachypithecus francoisi), and 1 red-shanked douc langur (Pygathrix nemaeus) from eight zoologic institutions. All institutions that responded were Association of Zoos and Aquariums, European Association of Zoos and Aquaria, or World Association of Zoos and Aquariums accredited. Males were more commonly represented in the total number of cases (86%), and all cases of obstructive urolithiasis occurred in males. The most common clinical signs observed in obstructive cases included stranguria (58.8%), lethargy (41.2%), anorexia (29.4%), depression (17.6%), and penile manipulation (11.8%). Clinicopathologic abnormalities revealed azotemia (76.5%), anemia (35.3%), and hyperkalemia (23.5%). Eleven of the 21 cases included urinalysis results, and crystalluria was reported in all 11. Obstructive cases were more commonly managed surgically, with medical management following. Instances of individual obstruction ranged from 0 (incidental finding) to 18, with a median of 8 (mean of 4.3) recurrent obstructions. A total of 39 urolith analyses were available from 17 of 21 cases, with calcium carbonate being the most common type isolated (37 of 39, 94.9%). Calcium oxalate was observed in the remaining 5.1% of cases (2 of 39). No cases exhibited a consistent match of crystalluria and urolith type. Death or euthanasia secondary to obstructive urolithiasis occurred in 52.4% of cases. Urinary obstruction secondary to urolithiasis appears to be a relevant cause of morbidity and mortality in Asian colobine species, and further study into etiology and preventive medicine should be undertaken.

SURVEY OF CLINICAL OPHTHALMIC DISEASE IN THE GIANT PANDA (AILUROPODA MELANOLEUCA) AMONG NORTH AMERICAN ZOOLOGICAL INSTITUTIONS.

This study surveyed six North American zoologic institutions to collect retrospective information on the incidence of ocular disease in the giant panda. Reported information included sex and age at presentation, as well as diagnosis, treatment, duration, and clinical outcome for each episode of ocular disease. Among the 42 animals included in the survey, 10 (23.8%) had clinical ocular abnormalities reported. Multiple disease episodes were reported in four animals, with 20 clinical episodes, and one additional animal who presented with corneal scarring from historic keratitis. Age at presentation varied from 0.4 to 26 yr (mean, 11.8 yr; median, 10.4 yr). Corneal abnormalities (including corneal opacity or haze, keratitis, corneal ulcers, and bullous keratopathy) were the most common pathologies reported, followed by conjunctivitis and/or ocular discharge. Additional reported abnormalities included limbal squamous cell carcinoma and lipid degeneration. Six cases resolved without intervention. Treatment protocols included topical and/or systemic medication with or without surgical intervention, which commonly resulted in resolution with or without persistent corneal scar. The prevalence of ocular disease identified in the giant panda in this study is higher than previous publications surveying ocular disease in the family Ursidae, indicating that this is an important source of morbidity in this species.

The Andean bear alopecia syndrome may be caused by social housing.

The Andean bear alopecia syndrome is a progressive and chronic condition documented in ex situ populations. Recent advances focus on treating symptoms, not preventing future cases. We therefore explored the epidemiology of this syndrome through an analysis of husbandry and veterinary conditions of 63 Andean bears (26M:37F) housed in North and South American zoos and other ex situ circumstances. We had the most complete information for the North American population and found that 29% of females (n = 24) were affected. No males (n = 26) were affected. An analysis of generalized linear models indicated that three models were competitive in describing the occurrence of the condition (i.e., ΔAICc ≤ 2): the model including only the individual's sex (χ2 = 13.41, df = 1, p < .001), the model including both individual sex and social housing status (χ2 = 1.36, df = 2, p < .001), and the model including both individual sex and the expression of stereotypical behaviors (χ2 = 13.82, df = 2, p = .001). Stereotypical behaviors were common among both males (50%, n = 26) and females (51.9%, n = 27) whether or not they were affected, but the syndrome was seen only in females who had been socially housed. Therefore, we suggest that the Andean bear alopecia syndrome is a symptomatic response to the long-term social housing of bears that would otherwise not live socially. To prevent new cases, we recommend that female Andean bears be housed with adult conspecifics only when females choose to cohabitate.

SEASONAL DERMATOPATHY AND CONCURRENT REPRODUCTIVE FINDINGS IN CAPTIVE FOSSA ( CRYPTOPROCTA FEROX).

Six female intact fossa ( Cryptoprocta ferox) in the San Diego Zoo collection presented with episodic, seasonal alopecia and variable pruritus between the years 1984 and 2015. Presentation was often accompanied by findings such as prominent palpable uterus or cervix and thickened, enlarged uterus on ultrasound. Dermatologic testing has been consistently nondiagnostic for primary cause of alopecia. Both the alopecia and reproductive findings have a higher occurrence from midspring to midsummer. Hormonal changes associated with reproductive activity are proposed as a possible explanation for the dermal clinical signs seen in these six fossas.

Tibial plateau leveling osteotomy in a cape clawless otter (Aonyx capensis) with cranial cruciate ligament ruptures.

A 13-yr-old female Cape clawless otter (Aonyx capensis) presented with an acute mild right pelvic limb lameness that progressed to a non-weight-bearing lameness. Diagnosis of a ruptured cranial cruciate ligament (CCL) was made based on positive cranial drawer during physical examination and was supported by radiographs. A surgical repair with a tibial plateau leveling osteotomy (TPLO) and bone anchor with an OrthoFiber suture was performed. The tibial plateau angle was reduced from 30 to 5 degrees. The otter returned to normal function after 12 wk of exercise restriction. Twelve months after surgery, the left CCL ruptured and a TPLO was performed. No complications developed after either surgery, and the otter had an excellent return to function. This is the first report of a cranial cruciate ligament rupture and TPLO procedure in a mustelid, supporting its application to noncanid and felid species.

Esophageal dissection and hematoma associated with obstruction in an Indian elephant (Elephas maximus indicus).

A 42-year-old female Indian elephant (Elephas maximus indicus) developed a sudden onset of excessive salivation and dysphagia. Esophageal obstruction was suspected; possibly related to palm frond ingestion. Esophageal endoscopy revealed a mat of plant material in the distal esophagus. An initial attempt at relieving the obstruction was unsuccessful, but subsequent use of custom-made instruments along with insufflation and hydropulsion enabled partial removal of the material. Postimmobilization care included aggressive intravenous and rectal fluids, anti-inflammatory and antibiotic administration, and fasting. Despite treatment, the dysphagia persisted and the elephant was euthanized due to lack of improvement and grave prognosis. Postmortem examination revealed remaining plant material in the esophagus, complicated by an esophageal dissection, mural hematoma, and secondary bacterial infection. Iatrogenic trauma may have contributed to the extent of esophageal injury. Although treatment was ultimately unsuccessful, the supportive care employed could potentially aid recovery in cases of less severe esophageal trauma.

Gastrointestinal torsions and intussusception in northern koalas (Phascolarctos cinereus) at San Diego Zoo (1976-2012).

The recent classification as threatened status of the northern koala (Phascolarctos cinereus) by the Australian Government highlights the importance of the conservation and health management of this iconic Australian marsupial. This case series describes gastrointestinal torsion and intussusception in six northern koalas (three males, three females, 2-11 yr old) at the San Diego Zoo from 1976 to 2012. Two koalas died shortly after presentation. Diagnoses of ileocecal intussusception, resulting from enteritis in one case and cecal torsion in the other, were made at postmortem examination. One koala died 4 days after an exploratory laparotomy, with negative findings, and an acute double colonic intussusception was diagnosed at postmortem examination. Two small intestinal mesenteric torsion and one proximal colon mesenteric torsion cases were successfully corrected surgically. In the case of colonic mesenteric torsion, the koala had recurrent clinical signs 2 wk later, and a second surgery requiring resection and anastomosis of ischemic jejunum was performed, with the koala dying shortly afterward. One koala with small intestinal torsion had a recurrence of torsion 22 mo later and subsequently died. The koala with the second case of small intestinal torsion remains alive 14 mo postsurgical correction. All six koalas presented with signs of colic that included anorexia, lethargy, depression, acute abdominal distension, abdominal stretching, decreased fecal output, open-mouth gasping, or a combination of symptoms. Abdominal radiographs may show stacked gastrointestinal linear gas patterns and contrast stasis. Prevalence of torsion and intussusception is low at this institution (2%), although recurrence in individuals is common (50%) and overall survival is poor (83%), which emphasizes the importance of timely recognition, surgical correction, and postoperative management. While inciting etiologies were unable to be determined in these cases, monitoring generalized gastrointestinal health and differing Eucalyptus sp. effects on individual koala's gastrointestinal function, parasite control, and stress minimization through standardized husbandry practices are likely important.

Characterization of progressive keratitis in otariids.

OBJECTIVE: To characterize a form of progressive keratitis that occurs commonly in otariids. MATERIALS AND METHODS: One hundred and thirteen captive otariids were evaluated by ophthalmologic examination and digital photography. RESULTS: Forty-six females and 67 males were in the reference population, average age of 14 years. California sea lions predominated (n = 100); there were also six Steller sea lions, five brown fur seals, one Guadalupe fur seal and one northern fur seal. Three stages of progressive keratitis are described. Overall, 64.6% animals and 142 eyes from 113 animals (62.8%) were affected with one of three stages. The mildest form, Stage 1 keratitis, occurred in 78 of 226 eyes (34.5%); the intermediate Stage 2 keratitis occurred in 30 of 226 eyes (13.3%); and the most severe, Stage 3 keratitis, occurred in 34 of 226 eyes (15%). All but six animals had bilateral disease. Animals with Stage 1 keratitis were significantly younger than those in more advanced stages. DISCUSSION: 'Otariid Keratitis' occurs in all populations of eared seals evaluated. A large-scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs. Age may be important since exposure accumulates with aging. Progression of the disease is also associated with secondary opportunistic bacterial and fungal infections. The surface immune system may be imbalanced contributing to these infections and progression.

Successful transabdominal subxiphoid pericardiostomy to relieve chronic pericardial effusion in a Sumatran orangutan (Pongo abelli).

A 46-yr-old female Sumatran orangutan (Pongo abelli) was first diagnosed with pericardial effusion in July 2006. Pericardiocentesis performed in January 2007 only provided short-term relief. In May 2007, a pericardial-peritoneal window was created using a transabdominal subxiphoid pericardiostomy technique, providing immediate and long-term relief. Seven months later, the orangutan was euthanized due to worsening heart failure, and no pericardial effusion was present. Transabdominal subxiphoid pericardiostomy offers a straightforward surgical approach that can provide significant relief in cases of chronic pericardial effusion in great apes.

Compressive myelopathy of the cervical spine in Komodo dragons (Varanus komodoensis).

Cervical subluxation and compressive myelopathy appears to be a cause of morbidity and mortality in captive Komodo dragons (Varanus komodoensis). Four cases of cervical subluxation resulting in nerve root compression or spinal cord compression were identified. Three were presumptively induced by trauma, and one had an unknown inciting cause. Two dragons exhibited signs of chronic instability. Cervical vertebrae affected included C1-C4. Clinical signs on presentation included ataxia, ambulatory paraparesis or tetraparesis to tetraplegia, depression to stupor, cervical scoliosis, and anorexia. Antemortem diagnosis of compression was only confirmed with magnetic resonance imaging or computed tomography. Treatment ranged from supportive care to attempted surgical decompression. All dragons died or were euthanatized, at 4 days to 12 mo postpresentation. Studies to define normal vertebral anatomy in the species are necessary to determine whether the pathology is linked to cervical malformation, resulting in ligament laxity, subsequent instability, and subluxation.

Repair of horn and frontal bone avulsion in a forest buffalo (Syncerus caffer nanus) with a polymethylmethacrylate dressing.

A 2-yr-old female forest buffalo (Syncerus caffer nanus) presented with acute trauma to the right horn following a fight with a conspecific resulting in fracture and avulsion of the frontal bone, cornual process, horn, and juxtaposed skin. The animal was sedated for wound care and debridement followed by placement of an antibacterial-impregnated polymethylmethacrylate (PMMA) dressing. The dressing was noted to be intact on examination at day 7 post-injury, but had become dislodged and had to be replaced at day 11 postinjury. The replacement dressing ultimately fell off 68 days post-injury, revealing a healed circular scar. The use of PMMA in this case provided optimal wound care. In the 6 yr since the injury, the animal has grown a nearly normal-appearing horn, suggesting that the noncornual skin and associated skull structures may retain the ability to differentiate into a near-normal appearing horn because the entire horn apparatus in this case was avulsed.

Molecular epidemiology of Mycobacterium avium subsp. avium and Mycobacterium intracellulare in captive birds.

Mycobacterium avium subsp. avium and Mycobacterium intracellulare are primary causes of mycobacteriosis in captive birds throughout the world, but little is known about how they are transmitted. To define the local epidemiology of infection, we strain-typed 70 M. avium subsp. avium and 15 M. intracellulare culture isolates obtained over a 4-year period from captive birds. Typing was performed using randomly amplified polymorphic DNA (RAPD) PCR, amplified fragment length polymorphic (AFLP) fragment analyses, and for a subset of isolates, DNA sequencing of a segment of the 16S-23S rRNA internal transcribed spacer region. Six strain clusters comprising 43 M. avium subsp. avium, isolates were identified; 42 isolates had unique typing patterns, including all M. intracellulare isolates. Phylo-geographical analyses using RAPD and AFLP fingerprints and animal confinement histories showed no correlation between housing of infected birds and mycobacterial strain-type, except for two animals. The diversity of M. avium subsp. avium and M. intracellulare isolates and minimal evidence for bird-to-bird transmission suggest that environmental reservoirs may be important sources of infection in captivity.

Transitional cell carcinomas in four fishing cats (Prionailurus viverrinus).

Transitional cell carcinomas (TCC) of the urinary bladder were diagnosed in four related fishing cats (Prionailurus viverrinus). The major clinical sign in each case was persistent hematuria unresponsive to medical therapy. Cystotomy and biopsy provided an antemortem diagnosis in three of the fishing cats before euthanasia because of progression of clinical signs. The diagnosis was made in the fourth cat after euthanasia because of renal failure. Hematuria improved temporarily in one of the cats diagnosed antemortem and treated with piroxicam and carboplatin. Attempts to isolate a herpesvirus in two of the cats failed. Histopathologic appearance of the TCC was similar to that described for other species. TCC metastasis to the lungs was noted at necropsy in one cat; metastatic disease was not noted in the other fishing cats on gross or histopathologic examination. TCC of the urinary bladder appears to be more prevalent in fishing cats than in other species of domestic or nondomestic felids.

Immobilization of Chacoan peccaries (Catagonus wagneri) using medetomidine, Telazol, and ketamine.

A combination of medetomidine, Telazol, and ketamine hydrochloride was used to immobilize captive Chacoan peccaries (Catagonus wagneri) for translocation within Paraguay during August-October 2002. Animals were darted in enclosed areas of varying size. The average dose used was 32.5+/-7.2 microg/kg of medetomidine, 0.63+/-0.2 mg/kg of Telazol, and 3.9+/-0.65 mg/kg of ketamine. First effects were noted at 4.3+/-2.1 min, and ability to handle the animals was achieved by 12.6+/-3.7 min. Heart and respiratory rates declined and oxygen saturation increased during anesthesia. Muscle relaxation was good. Atipamezole was used to antagonize the medetomidine, although recoveries were still slow. This drug combination provided adequate immobilization of Chacoan peccaries; however, this protocol would not be considered to be reversible, and confinement during recovery is recommended.