Publications (17)18.25 Total impact

  • S. Hoby · C. Wenker · M. Walkenhorst

    No preview · Article · Nov 2015
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    ABSTRACT: Pododermatitis is frequent in captive flamingos worldwide, but little is known about the associated histopathologic lesions. Involvement of a papillomavirus or herpesvirus has been suspected. Histopathologic evaluation and viral assessment of biopsies from 19 live and 10 dead captive greater flamingos were performed. Selected samples were further examined by transmission electron microscopy and immunohistochemistry. Feet from 10 dead free-ranging greater flamingos were also evaluated. The histologic appearance of lesions of flamingos of increasing age was interpreted as the progression of pododermatitis. Mild histologic lesions were seen in a 3-week-old flamingo chick with no macroscopic lesions, and these were characterized by Micrococcus-like bacteria in the stratum corneum associated with exocytosis of heterophils. The inflammation associated with these bacteria may lead to further histologic changes: irregular columnar proliferations, papillary squirting, and dyskeratosis. In more chronic lesions, hydropic degeneration of keratinocytes, epidermal hyperplasia, and dyskeratosis were seen at the epidermis, as well as proliferation of new blood vessels and increased intercellular matrix in the dermis. Papillomavirus DNA was not identified in any of the samples, while herpesvirus DNA was seen only in a few cases; therefore, these viruses were not thought to be the cause of the lesions. Poor skin health through suboptimal husbandry may weaken the epidermal barrier and predispose the skin to invasion of Micrococcus-like bacteria. Histologic lesions were identified in very young flamingos with no macroscopic lesions; this is likely to be an early stage lesion that may progress to macroscopic lesions. © The Author(s) 2015.
    Full-text · Article · Jan 2015 · Veterinary Pathology
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    ABSTRACT: The purpose of this study was to investigate the influence of feeding and UVB exposition on the occurrence and distribution patterns of vitamin D receptors (VDR) and calbindin D28k (Cb-D28k) in the gastrointestinal tract of veiled chameleons. Thus, 56 veiled chameleon hatchlings were divided into six treatment groups: UV (with UVB exposure); No (no supplements, no UVB exposure); CaAUV (with calcium (Ca), vitamin A supplementation, UVB exposure); CaA (with Ca, vitamin A supplementation); CaADUV (with Ca, vitamin A, vitamin D supplementation, UVB exposure); and CaAD (with Ca, vitamin A, vitamin D supplementation). Animals were reared under the suspected conditions for 6 months on locust-based diets. Tissue samples of stomach, duodenum, ileum and colon were taken, and semi-quantitative immunohistochemical methods (IHC) were performed to detect Cb-D28k and VDR. VDR immunoreactions were higher in the luminal epithelium of the duodenum than in that of the ileum. VDR immunoreactions in the luminal epithelium were higher at the base of the villi of the duodenum as compared to the tip. Cb-D28k immunoreactions were mainly observed in the luminal epithelium of the duodenum. The two groups treated with all dietary supplements (CaADUV, CaAD) exhibited a higher Cb-D28k immunoreaction as those with no supplements and UVB exposure only. No immunoreaction for both proteins could be detected in the stomach. This study suggests that the duodenum plays an important role in the active transcellular absorption of Ca in veiled chameleons as shown by the immunohistochemical detection of VDR and Cb-D28k. Expression of Cb-D28k, in particular, appears to be regulated by dietary supplementation of vitamin D and vitamin A. VDRs, however, tended to be upregulated when animals were not supplemented with Ca, vitamin D and vitamin A. This may be due to the decreased Ca concentrations which caused vitamin D activation in the skin without any supplementation, but UVB exposure.
    Full-text · Article · May 2014 · J Anim Physiol a Anim Nutr
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    ABSTRACT: Pododermatitis is a worldwide health and animal welfare problem in captive flamingos (Phoenicopteridae). Since sub-optimal substrate or flooring has been described as a factor in the development of pododermatitis in poultry and raptors, it is also suspected to play a role in flamingo foot health. Small groups of flamingos were separated from the main group in an indoor enclosure with artificial grass carpet and, in earlier years, concrete flooring, with additional fine granular sand in the water basin for the study year. Feet were evaluated before and after the separation. Judged subjectively, foot lesions had shown a general increase in the indoor enclosure in earlier years. In contrast, lesion severity and prevalence, scored in accordance with a standardised protocol, decreased when fine granular sand was provided. Since flamingos were observed mostly standing on sand and as this represented the major differentiating factor between years, it is concluded that fine granular sand is a favourable substrate to maintain, and one that may even lead to an improvement in flamingo foot health.
    No preview · Article · Feb 2014 · Animal welfare (South Mimms, England)
  • F Wyss · C Wenker

    No preview · Article · Jan 2014
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    F Wyss · C Wenker · N Robert · M Clauss · F von Houwald
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    ABSTRACT: Many case reports about different diseases in greater one-horned rhinoceroses (Rhinoceros unicornis) have been published, but an overview of the prevalence of diseases and an evaluation of causes of death is lacking. Necropsy reports of 106 greater one-horned rhinoceroses from 38 zoos worldwide were evaluated. Half of them were from adult animals, a third from perinatal deaths/stillbirths and the rest from juveniles and sub adults. Cardiac problems (cardiomyopathy, myocarditis, heart infarct) and cardiovascular failure due to gastrointestinal or pulmonary disease were the most frequent causes of death in adults. Among gastrointestinal problems, gastric ulcers and impactions, often with sand, were the most frequent findings. Sixteen adult greater one-horned rhinoceroses were euthanised, mainly due to chronic disease, foot problems or uterine leiomyomas. The two latter problems are suspected to be associated with obesity, and most of the animals with these problems were reported to be in good body condition at death. Leiomyomas are additionally thought to be predisposed by repeated oestrus cycles without pregnancy. Foot problems were only noted in 6 % of the animals and are probably underestimated in this dataset. Systematic documentation of necropsy findings is desirable, including complete animal identity, anamnesis, circumstances of death (natural death, euthanasia, and stillbirth), body condition scoring and weight.
    Full-text · Article · May 2012
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    S Hoby · M Clauss · A Aebischer · C Wenker · N Robert · A Liesegang
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    ABSTRACT: Although metabolic bone disease (MBD) is a very common disease in reptiles kept as pets, empirical data on the calcium (Ca) metabolism of reptiles are still scarce. We used the opportunity of a large-scale experimental study on growth and clinical manifestations of MBD in captive veiled chameleons (Chamaeleo calyptratus) to measure the apparent dry matter (DM) and Ca digestibility in 19 animals (6-49 g), receiving locust nymphs (Locusta migratoria) of two size classes (0.05 and 0.5 g) with or without supplementation of Ca, vitamin A and cholecalciferol (Group A: Ca 0.04-0.09%DM; Group B: Ca 0.47-0.84%DM). Dry matter digestibility was significantly lower for animals receiving smaller-sized prey. A regression analysis of dietary Ca vs. digestible Ca content revealed a complete 'true' digestibility of Ca for the range of investigated diets, which might indicate that requirements for this mineral were not yet exceeded by the diets used (so that a reduction in Ca absorption would be induced). Options of higher dietary Ca provision, and reactions of chameleons to such diets, should be further investigated.
    Full-text · Article · Jun 2011 · J Anim Physiol a Anim Nutr
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    H Nimmervoll · C Wenker · N Robert · S Albini
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    ABSTRACT: Three cases of fatal septicaemia due to Plesiomonas shigelloides and one due to Edwardsiella tarda were diagnosed in newborn penguins from the Basle Zoo, Switzerland from 2003 to 2007. The affected penguins were of two different species (king penguin, Aptenodytes patagonicus, and African penguin, Spheniscus demersus) and between 2 and 10 days old at the time of death. The causative agents, E. tarda and P. shigelloides are ubiquitous bacteria which are reported to be present in the normal intestinal flora of wild and captive aquatic animals, including penguins. Their occurrence and infectious potential is discussed.
    Full-text · Article · Mar 2011 · SAT Schweizer Archiv für Tierheilkunde
  • O. PAGAN · F. VON HOUWALD · C. WENKER · B. L. STECK
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    ABSTRACT: Little information is available in English on the keeping and breeding of the rarest equid species, the Critically Endangered Somali wild ass Equus africanus somalicus, in captivity. The husbandry experience gained by Basel Zoo over three decades of keeping this species is summarized with particular emphasis on management, nutrition and health.
    No preview · Article · Dec 2008 · International Zoo Yearbook
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    ABSTRACT: Scuticociliatosis is a disease of fish induced by ciliated parasites of the genus Scuticociliatida. It has been described in sea horses (Hippocampus sp.), flounders (Paralichthys olivaceus), and turbots (Scophthalmus maximus). Here we present a case study of a population of sea dragons chronically infected with scuticociliates identified as Philasterides dicentrarchi by histopathology and PCR. Beginning in 2004, over a period of 19 months, 10 sea dragons (Phycodurus eques and Phyllopteryx taeniolatus) were found dead in an aquarium of the Zoological Garden Basle, Switzerland. Clinically, the animals showed only faint symptoms of disease over a short period of time. At necropsy, macroscopic lesions were confined to the skin with multiple, often hemorrhagic, ulcerations. Histologically, epidermal ulcers were associated with necrosis and inflammation of the underlying dermis and musculature. Numerous ciliates, with a morphology consistent with scuticociliates, were present in these lesions. In several animals these ciliates had invaded blood vessels and were detected in gills and internal organs including kidney, thyroid gland, and central nervous system (CNS). In these organs, mild degenerative lesions and inflammatory reactions were evident. The ciliates were identified as Philasterides dicentrarchi based on small-subunit ribosomal RNA (SSUrRNA) gene sequences obtained by polymerase chain reaction (PCR) on DNA extracted from paraffin-embedded tissue sections. Our report shows that scuticociliate infections of sea dragons can develop into a systemic infection and that both species of sea dragons can be affected.
    Preview · Article · Aug 2008 · Veterinary Pathology
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    M Clauss · S Hammer · A Deb · S Knauf · O Martin Jurado · C Wenker · J M Hatt
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    ABSTRACT: In 2007, two different events for teaching principles in zoo and wildlife medicine and for introducing veterinary students to scientific work were organized, the “Zoo Research Camp 2007” at the Al Wabra Wildlife Preservation, Qatar, and the “First EAZWV Summer School” at Basle Zoo. Apart from support from the hosting facilities, events were organized by the Clinic of Zoo Animals, Exotic Pets and Wildlife of the Vetsuisse Faculty. The two events differed in concept – with more emphasis on research and data evaluation at the ZRC, and on lectures at the Summer School. Both events had in common that a limited group of students convened at a place different from their usual location, in a zoo setting, which was considered the key to their motivation and the success of the events. Here, we describe the two concepts in detail, also explaining the required commitments made by, and the benefits for, the participating hosts or organisations. We hope that other zoos will be open to host similar events in the future.
    Full-text · Article · May 2008
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    ABSTRACT: The decision to perform euthanasia in geriatric zoo mammals is usually a highly complex procedure involving ethical, medical, emotional and sometimes political factors. However, subsequent necropsies show that the pathological changes of organs and/or the musculoskeletal system are often already advanced. Therefore, we hypothesise that euthanasia is often delayed to the detriment of the animal's welfare. The purpose of this study was to facilitate and establish an initial, objective, decision-making framework for the euthanasia of geriatric zoo mammals. A scoring-system to assess the physical condition and quality of life in ageing zoo mammals is presented, based on retrospective and prospective investigation of 70 geriatric zoo mammals in five European zoos. Medical records and necropsy reports were studied in retrospective cases. Symptoms were monitored and recorded in prospective cases. Radiographic investigations under general anesthesia or at necropsy were performed additionally. A significant association between symptoms and pathological findings revealed that 36.9% (n = 24/65) of examined animals (n = 41/65) had pathological alterations to the musculoskeletal system and 26.2% (n = 17/65) suffered from neoplasia. Based on the individual reports, 28 veterinarians from different fields of veterinary medicine concluded that these animals had mild to severe pain, discomfort and a significantly reduced quality of life, thus strongly reducing welfare. The proposed scoring system includes all of these factors and offers a simple and reliable tool to support decision-making for euthanasia in geriatric zoo mammals.
    Full-text · Article · Aug 2007 · Animal welfare (South Mimms, England)
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    ABSTRACT: Primary renal tumors are rare neoplasms in nonhuman primates. This report describes a mixed epithelial and stromal tumor of the kidney (MESTK) in a 14.5-year-old female ringtail lemur. The well-demarcated, solid, and cystic mass was located in the pelvis of the left kidney and consisted histologically of both epithelial and mesenchymal components. The mesenchymal cells were arranged in fascicles around cysts lined by a well-differentiated epithelium. Neither the mesenchymal nor the epithelial parts showed significant nuclear atypia or mitotic figures. To our knowledge, only 1 similar case, classified as adenoleiomyofibromatous hamartoma, has been reported in a ringtail lemur. In humans this tumor affects predominantly perimenopausal women and can express estrogen and progesterone receptors. However, neither estrogen nor progesterone receptors could be identified by immunohistochemistry in the tumor of the present ringtail lemur. Therefore, a hormonal mechanism could not be demonstrated in this case.
    Full-text · Article · Apr 2007 · Veterinary Pathology
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    ABSTRACT: The first case of spongiform encephalopathy in a zebu (Bos indicus) was identified in a zoo in Switzerland. Although histopathologic and immunohistochemical analyses of the central nervous system indicated a diagnosis of bovine spongiform encephalopathy (BSE), molecular typing showed some features different from those of BSE in cattle (B. taurus).
    Full-text · Article · Jan 2007 · Emerging infectious diseases
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    Full-text · Conference Paper · May 2006
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    J M Hatt · C Wenker · J Castell · M Clauss

    Full-text · Article · Jan 2004
  • C. Wenker · S. Hoby · J. Völlm

    No preview · Article ·