Multiple endocrine neoplasia-like syndrome in 24 baboons (Papio spp.).

Multiple endocrine neoplasia (MEN) has not been reported in baboons, but this condition is well described in humans. An internal database was searched for all cases of concurrent endocrine hyperplasia and neoplasia in baboons. Twenty-four baboons (Papio spp.) with concurrent endocrine hyperplasia and neoplasia were identified. Twenty-one baboons had lesions in two endocrine organs, two baboons had lesions in three organs, and one baboon had lesions in four organs. Ten baboons aligned with the MEN1 classification; 14 baboons did not match any current human MEN classification. We report 24 cases of MEN-like syndrome in baboons. MEN1-like lesions accounted for nearly half (41%) of the affected animals. Genetic analysis of baboons with MEN-like syndrome could further elucidate the mechanisms of MEN and support the use of baboons as animal models for human MEN.

Coccidioidomycosis in Nonhuman Primates: Pathologic and Clinical Findings.

Coccidioidomycosis in nonhuman primates has been sporadically reported in the literature. This study describes 22 cases of coccidioidomycosis in nonhuman primates within an endemic region, and 79 cases of coccidioidomycosis from the veterinary literature are also reviewed. The 22 cases included baboons ( n = 10), macaques ( n = 9), and chimpanzees ( n = 3). The majority died or were euthanized following episodes of dyspnea, lethargy, or neurologic and locomotion abnormalities. The lungs were most frequently involved followed by the vertebral column and abdominal organs. Microscopic examination revealed granulomatous inflammation accompanied by fungal spherules variably undergoing endosporulation. Baboons represented a large number of cases presented here and had a unique presentation with lesions in bone or thoracic organs, but none had both intrathoracic and extrathoracic lesions. Although noted in 3 cases in the literature, cutaneous infections were not observed among the 22 contemporaneous cases. Similarly, subclinical infections were only rarely observed (2 cases). This case series and review of the literature illustrates that coccidioidomycosis in nonhuman primates reflects human disease with a varied spectrum of presentations from localized lesions to disseminated disease.

Diet-induced early-stage atherosclerosis in baboons: Lipoproteins, atherogenesis, and arterial compliance.

BACKGROUND: The purpose of this study was to determine whether dietary manipulation can reliably induce early-stage atherosclerosis and clinically relevant changes in vascular function in an established, well-characterized non-human primate model. METHODS: We fed 112 baboons a high-cholesterol, high-fat challenge diet for two years. We assayed circulating biomarkers of cardiovascular disease (CVD) risk, at 0, 7, and 104 weeks into the challenge; assessed arterial compliance noninvasively at 104 weeks; and measured atherosclerotic lesions in three major arteries at necropsy. RESULTS: We observed evidence of atherosclerosis in all but one baboon fed the two-year challenge diet. CVD risk biomarkers, the prevalence, size, and complexity of arterial lesions, plus consequent arterial stiffness, were increased in comparison with dietary control animals. CONCLUSIONS: Feeding baboons a high-cholesterol, high-fat diet for two years reliably induces atherosclerosis, with risk factor profiles, arterial lesions, and changes in vascular function also seen in humans.

Cytomegaloviral hypophysitis in a simian immunodeficiency virus-infected rhesus macaque (Macacca mulatta).

Rhesus macaques experimentally infected with Simian Immunodeficiency Virus (SIV) experience immunosuppression and often opportunistic infection. Among the most common opportunistic infections are rhesus cytomegalovirus (RhCMV), a ubiquitous betaherpesvirus that undergoes continuous low-level replication in immunocompetent monkeys. Upon SIV-mediated immunodeficiency, RhCMV reactivates and results in lesions in numerous organ systems including the nervous and reproductive systems. We report the first case of cytomegaloviral hypophysitis in a SIV-immunocompromised rhesus macaque.

Natural pathology of the captive chimpanzee (Pan troglodytes): A 35-year review.

We present the spontaneous pathological lesions identified as a result of necropsy or biopsy for 245 chimpanzees (Pan troglodytes) over a 35-year period. A review of the pathology database was performed for all diagnoses on chimpanzees from 1980 to 2014. All morphologic diagnoses, associated system, organ, etiology, and demographic information were reviewed and analyzed. Cardiomyopathy was the most frequent lesion observed followed by hemosiderosis, hyperplasia, nematodiasis, edema, and hemorrhage. The most frequently affected systems were the gastrointestinal, cardiovascular, urogenital, respiratory, and lymphatic/hematopoietic systems. The most common etiology was undetermined, followed by degenerative, physiologic, neoplastic, parasitic, and bacterial. Perinatal and infant animals were mostly affected by physiologic etiologies and chimpanzee-induced trauma. Bacterial and physiologic etiologies were more common in juvenile animals. Degenerative and physiologic (and neoplastic in geriatric animals) etiologies predominated in adult, middle aged, and geriatric chimpanzees.

Natural mortality and cause of death analysis of the captive chimpanzee (Pan troglodytes): A 35-year review.

We present the spontaneous causes of mortality for 137 chimpanzees (Pan troglodytes) over a 35-year period. A record review of the pathology database was performed and a primary cause of mortality was determined for each chimpanzee. The most common causes of mortality were as follows: cardiomyopathy (40% of all mortalities), stillbirth/abortion, acute myocardial necrosis, chimpanzee-induced trauma, amyloidosis, and pneumonia. Five morphologic diagnoses accounted for 61% of mortalities: cardiomyopathy, hemorrhage, acute myocardial necrosis, amyloidosis, and pneumonia. The most common etiologies were degenerative, undetermined, bacterial, traumatic, and neoplastic. The cardiovascular system was most frequently involved, followed by the gastrointestinal, respiratory, and multisystemic diseases. Degenerative diseases were the primary etiological cause of mortality of the adult captive chimpanzee population. Chimpanzee-induced trauma was the major etiological cause of mortality among the perinatal and infant population. This information should be a useful resource for veterinarians and researchers working with chimpanzees.

Spontaneous mediastinal myeloid sarcoma in a common marmoset (Callithrix jacchus) and review of the veterinary literature.

BACKGROUND: Myeloid sarcoma is a rare manifestation of myeloproliferative disorder defined as an extramedullary mass composed of myeloid precursor cells. A 9-month old, female, common marmoset (Callithrix jacchus) had increased respiratory effort. METHODS: A complete necropsy with histology and immunohistochemistry was performed. RESULTS: The thymus was replaced by a firm, gray-tan mass with a faint green tint, filling over 50% of the thoracic cavity. Sheets of granulocytes, lymphoid cells, nucleated erythrocytes, megakaryocytes, and hematopoietic precursors of indeterminate cell lineage replaced the thymus, perithymic connective tissue, mediastinal adipose tissues, epicardium, and much of the myocardium. The cells demonstrated diffuse strong cytoplasmic immunoreactivity for lysozyme, and strong, multifocal membranous immunoreactivity for CD117. CONCLUSION: We report the first case of a myeloid sarcoma in a common marmoset (C. jacchus), similar to reported human cases of mediastinal myeloid sarcoma, and present a review of myeloproliferative diseases from the veterinary literature.

Pauci-immune glomerulonephritis in a captive chimpanzee (Pan troglodytes), and a review of spontaneous cases in animals.

BACKGROUND: Crescentic glomeruli are the hallmark finding in rapidly progressive glomerulonephritis (RPGN) and are characterized by disruption and proliferation of the glomerular capsule and an influx of cells into Bowman's space. Pauci-immune-type RPGN is identified by a lack of immunoglobulins and immune complexes in the glomerular basement membrane. METHODS: Complete necropsy and histology were performed on the affected chimpanzee. Electron microscopy was performed on kidney sections. A search of the literature was performed to identify spontaneous RPGN in animals. RESULTS: We report a case of crescentic glomerulonephritis of the pauci-immune-type in a hepatitis C virus-infected 28-year-old male chimpanzee (Pan troglodytes) who was humanely euthanized for a cardiac-related decline in health. CONCLUSION: To our knowledge, this is the first report describing pauci-immune crescentic glomerulonephritis in a non-human primate.

An efficient model of human endometriosis by induced unopposed estrogenicity in baboons.

Endometriosis is a chronic estrogen-dependent disease that occurs in approximately 10% of reproductive age women. Baboons offer a clear benefit for studying the initiation and progression of endometriosis since baboon is very close to humans phylogenetically. Progestins are used in the treatment of endometriosis. The therapeutic window of progestins depends on the ratio of its affinity towards progesterone receptor agonism verses antagonism. The present study is to determine the role of pure antiprogestin in baboon endometriosis. We hypothesize that pure antiprogestin will induce unopposed estrogenicity and spontaneous endometriosis in baboons. The rate of endometrial invasion and attachment through modeled peritoneum in the presence and absence of progesterone and antiprogestin was evaluated in this study. A baboon model of endometriosis induced by unopposed estrogenicity using progesterone receptor antagonist (EC304) was used in this study. We observed EC304 has induced unopposed estrogenicity that deregulated proteins involved in attachment, invasion, cell growth, and steroid hormone receptors in this model. Our data suggest that depleting progesterone levels in the endometrium will increase estrogen hyper-responsiveness that leads to increased endometriotic lesion progression in the baboon (Papio anubis) model. This study reports a refined model of human endometriosis in baboons that could potentially be used to develop new diagnostic and therapeutic strategies for the benefit of women suffering from endometriosis.

Osteosarcoma in Baboons (Papio spp).

Bone neoplasms in baboons (Papio spp) are rare, with only one confirmed case of osteosarcoma previously described in the literature. Over a 12-y period, 6 baboons at a national primate research center presented with naturally occurring osteosarcoma; 3 lesions affected the appendicular skeleton, and the remaining 3 were in the head (skull and mandible). The 6 cases presented were identified in members of a large outdoor-housed breeding colony. The subjects were not genetically related or exposed to the same research conditions. Diagnoses were made based on the presentation and radiographic findings, with histologic confirmation.

Particle-to-PFU ratio of Ebola virus influences disease course and survival in cynomolgus macaques.

UNLABELLED: This study addresses the role of Ebola virus (EBOV) specific infectivity in virulence. Filoviruses are highly lethal, enveloped, single-stranded negative-sense RNA viruses that can cause hemorrhagic fever. No approved vaccines or therapies exist for filovirus infections, and infectious virus must be handled in maximum containment. Efficacy testing of countermeasures, in addition to investigations of pathogenicity and immune response, often requires a well-characterized animal model. For EBOV, an obstacle in performing accurate disease modeling is a poor understanding of what constitutes an infectious dose in animal models. One well-recognized consequence of viral passage in cell culture is a change in specific infectivity, often measured as a particle-to-PFU ratio. Here, we report that serial passages of EBOV in cell culture resulted in a decrease in particle-to-PFU ratio. Notably, this correlated with decreased potency in a lethal cynomolgus macaque (Macaca fascicularis) model of infection; animals were infected with the same viral dose as determined by plaque assay, but animals that received more virus particles exhibited increased disease. This suggests that some particles are unable to form a plaque in a cell culture assay but are able to result in lethal disease in vivo. These results have a significant impact on how future studies are designed to model EBOV disease and test countermeasures. IMPORTANCE: Ebola virus (EBOV) can cause severe hemorrhagic disease with a high case-fatality rate, and there are no approved vaccines or therapies. Specific infectivity can be considered the total number of viral particles per PFU, and its impact on disease is poorly understood. In stocks of most mammalian viruses, there are particles that are unable to complete an infectious cycle or unable to cause cell pathology in cultured cells. We asked if these particles cause disease in nonhuman primates by infecting monkeys with equal infectious doses of genetically identical stocks possessing either high or low specific infectivities. Interestingly, some particles that did not yield plaques in cell culture assays were able to result in lethal disease in vivo. Furthermore, the number of PFU needed to induce lethal disease in animals was very low. Our results have a significant impact on how future studies are designed to model EBOV disease and test countermeasures.

Mortality in captive baboons (Papio spp.): a-23-year study.

BACKGROUND: We report the causes of mortality for 4350 captive baboons that died or were euthanized due to natural causes during a 23 year period at the Southwest National Primate Research Center. METHODS: Necropsy records were retrieved and reviewed to determine a primary cause of death or indication for euthanasia. Data was evaluated for morphological diagnosis, organ system, and etiology. RESULTS: The 20 most common morphologic diagnoses accounted for 76% of the cases, including stillborn (10.8%); colitis (8.6%); hemorrhage (8.4%); ulcer (5.2%); seizures (4.7%); pneumonia (4.2%); inanition (4.1%); dermatitis (3.8%); spondylosis (3.3%); and amyloidosis (3.0%). The digestive system was most frequently involved (21.3%), followed by the urogenital (20.3%), cardiovascular (12.2%), and multisystem disease (10.3%). An etiology was not identified in approximately one-third of cases. The most common etiologies were trauma (14.8%), degenerative (9.5%), viral (8.7%), and neoplastic/proliferative (7.0%). CONCLUSION: This information should be useful for individuals working with baboons.

Serum prostate specific antigen changes in cynomolgus monkeys (Macaca fascicularis) on a high sugar high fat diet.

BACKGROUND: An inverse relationship between serum prostate specific antigen (PSA) levels and body mass index (BMI) has been reported in men but not in any animal model. METHODS: Serum PSA in a colony of cynomolgus monkeys was assayed and correlated to body weight, prostate weight, and age. In addition, 15 animals were selected and fed a high sugar high fat (HSHF) diet for 49 weeks to increase their BMI and correlate it to PSA RESULTS: Serum PSA levels were positively correlated to prostate weight (r = 0.515, P = 0.025) and age (r = 0.548, P = 0.00072) but was not significantly correlated to body weight (r = -0.032, P = 0.419). For the animals on the HSHF diet, body weight, lean mass, fat mass, and BMI were significantly higher at 49 weeks than at baseline (P < 0.01). PSA was not significantly correlated to body weight and insulin at both baseline and 49 weeks. PSA was negatively correlated to BMI and insulin resistance (HOMA-IR) at 49 weeks but not at baseline. In addition, we observed hepatic steatosis and increases in serum liver enzymes. CONCLUSIONS: Increases in BMI in cynomolgus monkeys as a result of consuming a HSHF diet resulted in PSA changes similar to those in humans with increased BMI. Cynomolgus monkeys are a useful model for investigating the relationship between obesity, diabetes, and PSA changes resulting from prostate gland pathology.

A preliminary report on the feeding of cynomolgus monkeys (Macaca fascicularis) with a high-sugar high-fat diet for 33 weeks.

BACKGROUND: The metabolic syndrome is common in populations exposed to a typical Western diet. There is a lack of an animal model that mimics this condition. METHODS: We fed 15 cynomolgus monkeys ad libitum a high-sugar high-fat (HSHF) diet for 33 weeks. Body weight, body composition, serum lipids, and insulin were measured at baseline and at 33 weeks. RESULTS: The animals tolerated the HSHF diet very well. In the intervention group, total serum cholesterol and low-density lipoprotein cholesterol were 3- and 5-fold higher, respectively, at 33 weeks as compared with their baseline levels. Serum high-density lipoprotein cholesterol and triglycerides were not significantly affected. Dual-energy X-ray absorptiometry (DXA) analysis of the intervention group indicated that the trunk fat mass increased by 187% during this period. CONCLUSIONS: Cynomolgus monkeys should be a useful model for investigating the interactions of diet and other factors such as genetics in the development of the metabolic syndrome.

Congenital anomalies in the baboon (Papio spp.).

BACKGROUND: A comprehensive survey of the prevalence of congenital anomalies in baboons has not been previously reported. We report the congenital anomalies observed over a 26-year period in a large captive baboon colony. METHODS: A computer search was performed for all baboon congenital anomalies identified at necropsy and recorded on necropsy submissions. RESULTS: We identified 198 congenital anomalies in 166 baboons from 9972 necropsies (1.66% of total necropsies). The nervous, urogenital, musculoskeletal, and cardiovascular systems were most commonly affected. The most common organs affected were the brain, bone, heart, testicle, kidney, penis, aorta, and skeletal muscle. The most frequent congenital anomalies were blindness, seizures, and hydrocephalus. CONCLUSIONS: The baboon has an overall frequency of congenital anomalies similar to humans and other non-human primates. Although the most frequently affected systems are similar, congenital anomalies involving the digestive system appear to be less common in the baboon.

Natural pathology of the Baboon (Papio spp.).

BACKGROUND: Baboons are useful animal models for biomedical research, but the natural pathology of the baboon is not as well defined as other non-human primates. METHODS: A computer search for all morphologic diagnoses from baboon necropsies at the Southwest National Primate Research Center was performed and included all the natural deaths and animals euthanized for natural causes. RESULTS: A total of 10,883 macroscopic or microscopic morphologic diagnoses in 4297 baboons were documented and are presented by total incidence, relative incidence by sex and age-group, and mean age of occurrence. The most common diagnoses in descending order of occurrence were hemorrhage, stillborn, amyloidosis, colitis, spondylosis, and pneumonia. The systems with the most diagnoses were the digestive, urogenital, musculoskeletal, and respiratory. CONCLUSION: This extensive evaluation of the natural pathology of the baboon should be an invaluable biomedical research resource.

Neoplasia in felids at the Knoxville Zoological Gardens, 1979-2003.

A review of medical records and necropsy reports from 1979-2003 found 40 neoplasms in 26 zoo felids, including five lions (Panthera leo, two males and three females), three leopards (Panthera pardus, two males and one female), one jaguar (Panthera onca, female), 11 tigers (Panthera tigris, three males and eight females), two snow leopards (Panthera uncia, one male and one female), two cougars (Felis concolor, one male and one female), one bobcat (Felis rufus, male), and one cheetah (Acinonyx jubatus, female). Animals that had not reached 3 yr of age or had been housed in the collection less than 3 yrs were not included in the study. Neoplasia rate at necropsy was 51% (24/47), and overall incidence of felid neoplasia during the study period was 25% (26/103). Neoplasia was identified as the cause of death or reason for euthanasia in 28% (13/47) of those necropsied. Neoplasms were observed in the integumentary-mammary (n=11), endocrine (n=10), reproductive (n=8), hematopoietic-lymphoreticular (n=5), digestive (n=3), and hepatobiliary (n=2) systems. One neoplasm was unclassified by system. Multiple neoplasms were observed in 11 animals. Both benign and malignant neoplasms were observed in all systems except for the hematopoietic-lymphoreticular systems where all processes were malignant. Of the endocrine neoplasms, those involving the thyroid and parathyroid glands predominated (n=8) over other endocrine organs and included adenomas and carcinomas. In the integumentary system, 63% (7/11) of neoplasms involved the mammary gland, with mammary carcinoma representing 83% (6/7) of the neoplasms. The rates of neoplasia at this institution, during the given time period, appears to be greater than rates found in the one other published survey of captive felids.

Cholangiectasis and duodenal diverticulosis in a farm-raised elk (Cervus elaphus).

A 6-year-old male elk presented in August with a 4-month history of weight loss and a 1-day history of being recumbent and unable to rise. The elk's body condition score was 1.5/5. Hematology and blood chemistry showed an inflammatory leukogram, mild electrolyte abnormalities, and elevated liver enzyme activities. Because of poor prognosis, the owner elected euthanasia. On necropsy, 8 diverticula were in the duodenum distal to the common bile duct, which was dilated and filled with feed material. Many intrahepatic bile ducts were dilated up to 5 cm, were filled with ingesta and gritty material, and had walls thickened up to 1.5 mm. On histologic examination, mural thickening of dilated bile ducts was because of increased fibrous connective tissue with inflammatory cell infiltration and hyperplastic and hypertrophic epithelial lining. Portal tracts diffusely contained hyperplastic bile ducts and had increased amounts of fibrous connective tissue. Abscesses that contained bacteria were scattered throughout the liver. Duodenal diverticula lacked the tunica muscularis, and the muscularis mucosa was hypertrophied. Caudal to some diverticula, the duodenal lumen was narrowed. An additional finding was embolic pneumonia with fungi morphologically and immunohistochemically consistent with Aspergillus spp.

Hepatic yersiniosis in a cougar (Felis concolor).

A cougar (Felis concolor) was diagnosed with hepatic yersiniosis by bacterial culture and histopathology. The animal had a 2-week history of anorexia and jaundice before its death. Grossly, the liver exhibited caseo-necrotic foci. Histopathologically, there was necrotizing and suppurative hepatitis, with large numbers of intralesional gram-negative coccobacilli. Additional hepatic lesions included central vein thrombosis, lymphoplasmacytic portal hepatitis, and capsulitis. Yersinia pseudotuberculosis coccobacilli were isolated in pure culture from the hepatic lesions. Because the hepatic lesions in this animal resemble those of other zoonotic diseases, such as plague and tularemia, veterinarians and laboratory personnel who handle samples should take adequate safety precautions. This report is the first to describe the pathology associated with hepatic yersiniosis in a cougar.