Chronic Kidney Disease and Kidney Stone in a Wild Chimpanzee (Pan troglodytes verus) in Côte d'Ivoire.

An older wild female chimpanzee (Pan troglodytes) was found dead with a large calcium oxalate stone in the renal pelvis. Histopathological changes included glomerulosclerosis, interstitial nephritis and fibrosis, focal mineralization, and medial hypertrophy. Urinary albumin-creatinine-ratio showed increased values from 15 months before death. Causes of the kidney disease remain unconfirmed.

Systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus).

Systemic amyloid light-chain (AL) amyloidosis is an infrequent disease in which amyloid fibrils derived from the immunoglobulin light chain are deposited in systemic organs, resulting in functional impairment. This disease has been notably uncommon in animals, and nonhuman primates have not been reported to develop it. In this study, we identified the systemic AL kappa chain amyloidosis in a captive Bornean orangutan (Pongo pygmaeus) and analyzed its pathogenesis. Amyloid deposits were found severely in the submucosa of the large intestine, lung, mandibular lymph nodes, and mediastinal lymph nodes, with milder lesions in the liver and kidney. Mass spectrometry-based proteomic analysis revealed an abundant constant domain of the immunoglobulin kappa chain in the amyloid deposits. Immunohistochemistry further confirmed that the amyloid deposits were positive for immunoglobulin kappa chains. In this animal, AL amyloidosis resulted in severe involvement of the gastrointestinal submucosa and lymph nodes, which is consistent with the characteristics of AL amyloidosis in humans, suggesting that AL amyloid may have a similar deposition mechanism across species. This report enhances the pathological understanding of systemic AL amyloidosis in animals by providing a detailed characterization of this disease based on proteomic analysis.

Granulomatous meningoencephalitis and blindness associated with Mycobacterium tuberculosis complex infection in a senile female chimpanzee (Pan troglodytes).

A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis.

ACUTE NECROTIZING AND EOSINOPHILIC MYOCARDITIS IN A CHIMPANZEE (PAN TROGLODYTES).

Cardiac disease is of importance in captive chimpanzee (Pan troglodytes) health. Here we report an eosinophilic and necrotizing myocarditis in a 17-y-old chimpanzee with no previous history of cardiac disease that progressed to death within 48 h. Toxic and infectious causes were ruled out. The chimpanzee had eosinophilia at different occasions in previous years. The animal had a severe, diffuse, and acute monophasic necrotizing myocarditis, with a moderate lymphoplasmacytic infiltrate that was rich in eosinophils. Ante- and postmortem investigations are compatible with an unusual eosinophilic myocarditis with clinical evolution and morphology comparable with human eosinophilic myocarditis secondary to hypereosinophilic syndrome.

MANAGEMENT OF MEDICAL COMPLICATIONS ASSOCIATED WITH A PRESUMED TETANUS INFECTION IN A NORTHWEST BORNEAN ORANGUTAN (PONGO PYGMAEUS PYGMAEUS).

An 18-yr-old female orangutan (Pongo pygmaeus pygmaeus) developed opisthotonus after sustaining conspecific bite wounds 3 wk earlier. The orangutan developed progressive tetraparesis and dysphagia, despite normal mentation, suggestive of tetanus. A tetanus vaccine had been administered at 2 yr of age, but none since. Brain magnetic resonance imaging, computed tomography, cerebral spinal fluid tap, and bloodwork were unremarkable. Viral, Baylisascaris, and tetanus toxin testing were negative. A femoral central venous catheter (CVC) was placed to provide medications, fluids, and parenteral nutrition. The orangutan received human tetanus immunoglobulin, tetanus toxoid, penicillin, methocarbamol, and analgesia. After 1 wk, the catheterized limb became edematous; a deep vein thrombosis (DVT) was diagnosed ultrasonographically. A cephalic CVC was placed, the limb casted, intravenous therapy reinitiated, and enoxaparin started. The orangutan became mobile days later, and progressively improved. Despite no compliance with enoxaparin, the DVT resolved without residual signs. This is the first reported case of presumptive tetanus and DVT in a great ape.

The character of parietal and orbital alterations in the superfamily Hominoidea (families Hominidae [exclusive of Homo] and Hylobotidae).

Parietal external surface disruption routinely referred to as porotic hyperostosis, and orbital alterations (cribra orbitalia), have been attributed to anemia-related bone marrow hyperplasia in humans. A recent study in humans identified that they were actually vascular in nature. Skeletons were examined and epi-illumination surface microscopy was performed on the parietal region and orbit of 156 Hominidae and 123 Hylobotidae to assess if these phenomena were trans-phylogenetic. Trans-cortical channels were recognized on the basis of visualized ectocranial surface defects penetrating the parietal; cribra orbitalia, by alteration of the normally smooth orbital roof appearance. Trans-cortical parietal channels, ranging in size from 20 to 100 µm, are rare in Gorilla and Pan troglodytes and absent in Pan paniscus. They are universally present in adult Pongo abeli and in Hylobatidae, independent of species. Cribra orbitalia was common in Hylobotidae, Pongo pygmaeus and P. abelii, less prevalent in adult P. troglodytes, and not recognized in any Gorilla gorilla or P. paniscus examined. The proliferative form predominated, with the exception of Hylobates concolor and muelleri, in which uncalcified vascular grooves predominated. No correlation was observed between the presence of either trans-cortical channels or cribra orbitalia and fractures, osteoarthritis, or inflammatory arthritis. Parietal alterations observed in apes are trans-cortical channels, analogous to those observed in humans, and do not represent porosity. Similarly, cribra orbitalia in apes is confirmed as vascular in nature. The proliferative form apparently represents calcification of blood vessel walls, indistinguishable from observations in humans. Predominant presence in adults rather than in juveniles suggests that both forms are acquired rather than developmental in derivation. Sex and bone alteration/disease-independence suggests that mechanical, endocrine, and inflammatory phenomena do not contribute to the development of either. Further, independent occurrence of trans-cortical channels and cribra orbitalia suggests that they do not have a shared etiology.

Brunner's gland hyperplasia in a geriatric chimpanzee (Pan troglodytes), an infrequently reported lesion.

Benign duodenal tumours have very rarely been reported in captive non-human primates and are also rare in human beings. Brunner's gland hyperplasia has not been fully described in a non-human primate. Here, we report Brunner's gland hyperplasia in a geriatric chimpanzee, which was an incidental finding during post-mortem examination.

Discovery of os cordis in the cardiac skeleton of chimpanzees (Pan troglodytes).

Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the cardiac skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of cardiac arrhythmias and sudden death.

Acute human orthopneumovirus infection in a captive white-handed gibbon.

We report herein a fatal case of acute human orthopneumovirus (formerly respiratory syncytial virus) infection in a captive white-handed gibbon (Hylobates lar). Other members of the housing group had mild respiratory signs. Gross examination revealed bilateral pulmonary congestion and froth in the bronchi. Microscopically, the lungs had lymphocytic, neutrophilic infiltration of the interstitium and alveolar walls. There was necrosis of terminal bronchiolar epithelium and terminal bronchioles, and surrounding alveoli contained necrotic and exfoliated epithelial cells admixed with histiocytes and syncytial cells. Additional lesions included nonsuppurative meningoencephalitis, and epidermal hyperkeratosis and hyperplasia with syncytial cell formation. PCR screening for 12 human respiratory viruses was positive for orthopneumovirus in multiple tissues, including lung, and immunohistochemical staining for human orthopneumovirus detected viral antigen within bronchial epithelial cells. IHC and PCR for measles virus on preserved sections were negative. White-handed gibbons have not been previously reported as hosts for human orthopneumovirus, an important respiratory pathogen of both primates and humans.

Placenta Accreta in an Oragnutan (Pongo abelii) and a Chimpanzee (Pan troglodytes).

Placenta accreta is defined as abnormal adherence of the placenta to the uterine wall. Placenta accreta is recognized as a common problem in human medicine, but has apparently not been reported previously in great apes, despite similarity in their reproductive biology. A 36-year-old multiparous female Sumatran orangutan (Pongo abelii) and a 20-year-old nulliparous female chimpanzee (Pan troglodytes), with gross uterine and histological uterine vascular changes that are characteristic of placenta accreta, are presented.

Idiopathic Myocardial Fibrosis in Captive Chimpanzees (Pan troglodytes).

Cardiovascular disorders and predominantly idiopathic myocardial fibrosis are frequently associated with mortality among zoo-housed chimpanzees (Pan troglodytes). Formalin-fixed whole hearts of deceased chimpanzees housed in zoos (n = 33) and an African sanctuary (n = 2) underwent detailed macroscopic and histopathologic examination using a standardized protocol. Archived histological slides from the hearts of 23 additional African sanctuary-housed chimpanzees were also examined. Myocardial fibrosis (MF) was identified in 30 of 33 (91%) of the zoo-housed chimpanzees but none of the 25 sanctuary-housed chimpanzees. MF was shown to be characterized by both interstitial and replacement fibrosis. Immunophenotyping demonstrated that the fibrotic lesions were accompanied by the increased presence of macrophages, alpha smooth muscle actin-positive myofibroblasts, and a minimal to mild T-cell-dominant leukocyte infiltration. There was no convincing evidence of cardiotropic viral infection or suggestion that diabetes mellitus or vitamin E or selenium deficiency were associated with the presence of the lesion. However, serum vitamin D concentrations among zoo-housed chimpanzees were found to be lower in seasons of low ultraviolet light levels.

DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS IN CAPTIVE GORILLAS (GORILLA SPP.): APPEARANCES AND DIAGNOSIS.

Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder of unknown cause, in which new bone forms in soft tissues attached to the skeleton. Originally described in humans, in whom it is quite common, it is usually asymptomatic. New bone may completely bridge across joints, especially in the spine. However, it can be difficult to distinguish from diseases such as spondyloarthritis and spondylosis. With safer and increased use of radiography in diagnosis, the unfamiliar skeletal changes of asymptomatic DISH may now be coincidentally revealed during investigation of other disorders and result in misdiagnosis and unnecessary treatment. There have been case reports of its occurrence in great apes, but this is the first study to illustrate its appearances in a series of 11 skeletons of western and eastern lowland gorillas (Gorilla gorilla gorilla and Gorilla beringei graueri) from zoos in Europe and the United States. The study combines a review of available clinical and postmortem records with examination of the skeletons and radiologic investigation, such as computed tomography (CT). The results indicate that the disorder is probably common in older (>30 yr) captive gorillas, but that it is asymptomatic. It was not symptomatic during life in any of these animals. Several cases had unexpected features, such as extensive involvement of the thorax and extra-articular sacroiliac and tibiofibular joint fusions that are not typical in humans. By illustrating these skeletons, the study should aid differentiation of DISH from spondylosis (syn spondylosis deformans) and spondyloarhritis. It illustrates those features that are atypical of human DISH. CT scanning is valuable in such cases for examining diagnostically important areas such as sacroiliac joints. Increased awareness of DISH should help with understanding its cause, both in gorillas and humans.

Faster growth corresponds with shallower linear hypoplastic defects in great ape canines.

Deeper or more 'severe' linear enamel hypoplasia (LEH) defects are hypothesized to reflect more severe stress during development, but it is not yet clear how depth is influenced by intrinsic enamel growth patterns. Recent work documented inter- and intraspecific differences in LEH defect depth in extant great apes, with mountain gorillas having shallower defects than other taxa, and females having deeper defects than males. Here, we assess the correspondence of inter- and intraspecific defect depth and intrinsic aspects of enamel growth: enamel extension rates, outer enamel striae of Retzius angles, and linear enamel thickness. Thin sections of great ape canines (n = 40) from Gorilla beringei beringei, Gorilla gorilla gorilla, Pan troglodytes, and Pongo spp. were analyzed. Enamel extension rates were calculated within deciles of enamel-dentine junction length. Linear enamel thickness and the angle of intersection between striae of Retzius and the outer enamel surface were measured in the imbricational enamel. Mountain gorillas have faster enamel extension rates and shallower striae angles than the other taxa examined. Mountain gorillas have thinner imbricational enamel than western lowland gorillas and orangutans, but not chimpanzees. In the combined-taxon sample, females exhibit larger striae angles and thicker imbricational enamel than males. Enamel extension rates are highly negatively correlated with striae angles and LEH defect depth. Enamel growth variation corresponds with documented inter- and intraspecific differences in LEH defect depth in great ape canines. Mountain gorillas have shallower striae angles and faster extension rates than other taxa, which might explain their shallow LEH defect morphology and the underestimation of their LEH prevalence in previous studies. These results suggest that stressors of similar magnitude and timing might produce defects of different depths in one species or sex vs. another, which has implications for interpretations of stress histories in hominins with variable enamel growth patterns.

CONGENITAL HYPOTHYROIDISM IN A BORNEAN ORANGUTAN (PONGO PYGMAEUS) AND A SUMATRAN ORANGUTAN (PONGO ABELII).

Congenital hypothyroidism (CH) in humans is most commonly caused by disruption of thyroid gland development (dysgenesis) or an inherited defect in thyroid hormone biosynthesis (dyshormonogenesis). CH has not been previously documented in great apes. This report describes the clinical presentation, diagnosis, and treatment of CH in a 9-mo-old male Bornean orangutan (Pongo pygmaeus) and a 6-wk-old female Sumatran orangutan (Pongo abelii). Primary CH due to thyroid dysgenesis was confirmed in the Bornean orangutan using sonography and radioisotope scintigraphy. Although commercial thyroid immunoassays are not validated for use in orangutans, in comparison to age-matched controls, thyroid-stimulating hormone level was markedly elevated, and serum thyroxine (T4) and free T4 levels were markedly decreased in both cases. Oral supplementation with levothyroxine sodium resulted in noticeable clinical improvement in both orangutans within 30 days of initiating treatment.

Cardiac disease is linked to adiposity in male gorillas (Gorilla gorilla gorilla).

Cardiac disease is a major cause of morbidity and mortality for adult gorillas. Previous research indicates a sex-based difference with predominantly males demonstrating evidence of left ventricular hypertrophy. To evaluate these findings, we analyzed serum markers with cardiac measures in a large sample of gorillas. The study sample included 44 male and 25 female gorillas housed at American Association of Zoo and Aquariums (AZA)-accredited zoos. Serum samples were collected from fasted gorillas during routine veterinary health exams and analyzed to measure leptin, adiponectin, IGF-1, insulin, ferritin, glucose, triglycerides, and cholesterol. Cardiac ultrasonography via transthoracic echocardiogram was performed simultaneously. Three echocardiographic parameters were chosen to assess cardiac disease according to parameters established for captive lowland gorillas: left ventricular internal diameter, inter-ventricular septum thickness, and left ventricular posterior wall thickness. Our data revealed that high leptin, low adiponectin, and lowered cholesterol were significantly and positively correlated with measures of heart thickness and age in males but not in females. Lowered cholesterol in this population would be categorized as elevated in humans. High leptin and low adiponectin are indicative of increased adiposity and suggests a potential parallel with human obesity and cardiovascular disease in males. Interestingly, while females exhibited increased adiposity with age, they did not progress to cardiac disease.

OUTCOMES OF SNARE-RELATED INJURIES TO ENDANGERED MOUNTAIN GORILLAS ( GORILLA BERINGEI BERINGEI) IN RWANDA.

Mountain gorillas ( Gorilla beringei beringei) are one of the most critically endangered great apes in the world. The most common cause of mountain gorilla morbidity and mortality is trauma (e.g., injury from conspecifics or snare entrapment). We conducted a retrospective case-control study of free-ranging, human-habituated mountain gorillas to evaluate factors associated with snare entrapment and the results of clinical intervention. Data were collected from clinical records on all clinical intervention cases ( n=132) in Volcanoes National Park, Rwanda, conducted between 1995-2015. Wildlife veterinarians treated 37 gorillas entrapped in snares and 95 gorillas for other clinical conditions (including trauma and respiratory illness). Multivariate statistical analyses revealed that young gorillas (<8 yr old) were more likely than older gorillas to become snared; that comorbidities delayed times to intervention (≥3 d); and that severity of wounds at the time of intervention were associated with increased risk of lasting impairment (including loss of limb or limb function, or death) within 1 mo after intervention. Our results may influence decisions for gorilla health monitoring and treatment to most effectively conserve this critically endangered species.

ANTEMORTEM DIAGNOSIS AND SUCCESSFUL TREATMENT OF A COMPLETE MOLAR PREGNANCY IN A GERIATRIC BONOBO ( PAN PANISCUS).

A 47-yr-old multiparous female bonobo ( Pan paniscus) tested positive for pregnancy on a routine urine test. Because this geriatric animal was considered postreproductive, oral contraception had been discontinued. Sequential transabdominal ultrasound evaluations were performed under voluntary behavior and revealed that the uterus contained a mass of heterogenous tissue which was rapidly increasing in size. Due to a lack of normal fetal development and the ultrasonographic appearance of the uterine tissue, a molar pregnancy was suspected. Ovariohysterectomy was performed, and a complete hydatidiform mole was confirmed through human chorionic gonadotropin levels as well as gross and histological examination of the uterus. To the authors' knowledge, this is the first time a complete molar pregnancy has been reported antemortem in a nonhuman great ape, although a single case of partial hydatidiform mole was previously documented in a chimpanzee on postmortem examination. This case describes the successful medical and surgical management of complete molar pregnancy in a bonobo and provides support for extending the age range of birth control recommendations in geriatric captive great apes that exhibit active breeding behavior.

A case of benign osteogenic tumour in Homo naledi: Evidence for peripheral osteoma in the U.W. 101-1142 mandible.

The reported incidence of neoplasia in the extinct hominin record is rare. We describe here the first palaeopathological analysis of an osteogenic lesion in the extinct hominin Homo naledi from Dinaledi Cave (Rising Star), South Africa. The lesion presented as an irregular bony growth, found on the right lingual surface of the body of the adult mandible U.W. 101-1142. The growth was macroscopically evaluated and internally imaged using micro-focus x-ray computed tomography (µCT). A detailed description and differential diagnosis were undertaken using gross and micromorphology, and we conclude that the most probable diagnosis is peripheral osteoma - a benign osteogenic neoplasia. These tumours are cryptic in clinical expression, though they may present localised discomfort and swelling. It has been suggested that muscle traction may play a role in the development and expression of these tumours. The impact of this lesion on the individual affected is unknown. This study adds to the growing corpus of palaeopathological data from the South African fossil record, which suggests that the incidence of neoplastic disease in deep prehistory was more prevalent than traditionally accepted. The study also highlights the utility of micro-computed tomography in assisting accurate diagnoses of ancient pathologies.

Vernal-like conjunctivitis in a western lowland gorilla (Gorilla gorilla gorilla).

CASE DESCRIPTION: A 17-year-old female western lowland gorilla presented with bilateral ocular discharge, conjunctivitis, and rhinitis that was investigated and treated over a 34-month period. Clinical findings, diagnostic results, treatment, and follow-up are described. CLINICAL FINDING: A mild intermittent mucoid ocular discharge was initially noted. 10 months later, conjunctival hyperemia and thickening developed and progressed rapidly to a mass-like lesion covering the right eye. Hematology revealed eosinophilia. Conjunctival cytology revealed eosinophils and neutrophils, and histopathology revealed a chronic proliferative eosinophilic conjunctivitis. 21 months after, the ocular lesions were investigated the gorilla developed masses within both external nares. Histopathology of the nasal lesions revealed chronic-active eosinophilic rhinitis. TREATMENT AND OUTCOME: Treatment of the gorilla was based on protocols recommended for human patients. Protocols for mild, moderate, and finally severe disease were used, involving topical and oral combinations of treatments. The gorilla eventually responded to systemic immunosuppressant therapy recommended for severe refractory disease. CLINICAL SIGNIFICANCE: To the authors' knowledge, this is the first reported case of vernal-like conjunctivitis in a western lowland gorilla.