[Trichophyton mentagrophytes-from snow leopard to man : A molecular approach for uncovering the chain of infection]. / Trichophyton mentagrophytes ­ vom Schneeleoparden zum Menschen : Ein molekularer Ansatz zur Aufdeckung der Infektionskette.

Sources of infection for Trichophyton (T.) mentagrophytes-a zoophilic dermatophyte-comprise pet rodents (guinea pigs, mice, rabbits) and sometimes cats. Human infections due to dermatophytes after contact with zoo animals, however, are extreme rare. Four zoo keepers from Basel Zoo were diagnosed to suffer from tinea manus and tinea corporis due to T. mentagrophytes. The 22-year-old daughter of one zoo keeper was also infected with tinea corporis after having worked in the snow leopard section for one day. The strain of the index patient was confirmed by a direct uniplex-PCR-EIA and sequence analysis of the ribosomal internal transcribed spacer (ITS) region (18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA) as T. mentagrophytes. Three young snow leopards from Basel Zoo were identified as the origin of the fungal skin infection. The transmission occurred due to direct contact of the zoo keepers with the young snow leopards when removing hedgehog ticks (Ixodes hexagonus). Two adult snow leopards had developed focal alopecia of the facial region which was diagnosed as dermatomycoses due to T. mentagrophytes by the zoo veterinarians. By sequence analysis, both the strains from the animals and a single strain of the index patient showed 100% accordance proving transmission of T. mentagrophytes from animals to the zoo keepers. Molecular biological identification revealed a strong relationship to a strain of T. mentagrophytes from European mink (Mustela lutreola) from Finland. Treatment of patients was started using topical ointment with azole antifungals, and oral terbinafine 250 mg once daily for 4 weeks. Both adult snow leopards and the asymptomatic young animals were treated with oral itraconazole.

Piscine mycobacteriosis - Involvement of bacterial species and reflection in pathology.

INTRODUCTION: Piscine mycobacteriosis is a lethal disease with zoonotic potential, found worldwide in both fresh and marine fish. More than 20 strains of Mycobacterium spp. are known to persist in fish so far, but the pathogenicity is currently unknown for most of them. However, M. marinum is reported as one of the most pathogenic agents for fish and is involved in zoonotic cases. We examined 47 different cases from two zoological gardens, where fish tuberculosis was identified or previously suspected during the last ten years. We collected PCR and sequencing data, which were then compared to previously collected clinical data and pathology. The clinical signs caused by Mycobacterium spp. were similar in all the cases, except for cases infected by M. marinum, which lacked the presence of skin lesions. Lesions seen in histology caused by M. marinum tended to be more acute and severe compared lesions caused by other Mycobacterium spp. The majority of M. marinum cases have been reported within marine fish. In contrast to previous studies we detected this species to be the predominant bacteria present within freshwater fish. Interestingly, we detected M. holsaticum in one of the seawater systems used in this project, being the first report of this Mycobacterium species shown to be present in a fish.

INTRODUCTION: La mycobactériose du poisson est une maladie létale avec un potentiel zoonotique qui se trouve dans le monde entier chez les poissons d'eau douce et marins. Plus de 20 souches de Mycobacterium spp. sont à ce jour connues chez les poissons, mais la pathogénicité est actuellement inconnue pour la plupart d'entre elles. Cependant, M. marinum est signalé comme l'un des agents les plus pathogènes pour les poissons et il est impliqué dans des cas de zoonoses. Nous avons examiné 47 cas différents provenant de deux jardins zoologiques où la tuberculose du poisson a été identifiée ou suspectée au cours des dix dernières années. Nous avons recueilli des données de PCR et de séquençage qui ont ensuite été comparées aux données cliniques et à la pathologie précédemment collectées. Les signes cliniques causés par Mycobacterium spp. étaient similaires dans tous les cas, à l'exception des cas infectés par M. marinum, chez lesquels manquaient les lésions cutanées. Les lésions histologiques observées dans les infections par M. marinum tendaient à être plus aiguës et graves comparées aux lésions provoquées par d'autres espèces de Mycobacterium spp. La majorité des cas de M. marinum ont été documentés chez des poissons marins. Contrairement aux études précédentes, nous avons constaté que cette espèce était la principale bactérie présente chez les poissons d'eau douce. Fait intéressant, nous avons détecté M. holsaticum dans l'un des systèmes d'eau de mer examinés dans ce projet, ce qui est le premier cas confirmé de la présence de cette espèce de Mycobacterium chez un poisson.

[Chromosomal aberrations in a subfertile cotton-top tamarin]. / Chromosomen-Veränderungen bei einem subfertilen Lisztäffchen.

INTRODUCTION: The present case report describes a female cotton-top tamarin which was taken over by the Zoo Basel to form a new breeding pair. The animal demonstrated increased marking behavior without any obvious medical reasons, dominant behavior, failure to become pregnant and its external genitals were ambiguous. A disorder of the sexual development (DSD) was suspected by the zoo veterinarians and in a first step, the chromosomes of the monkey were analyzed. Six cell lines with different karyotypes were observed. The two most frequent cell lines had a 46,XX or a 46,XY karyotype which are normal chromosome complements of female and male cotton-top tamarins, respectively. The other much less frequent cell lines showed numerical aberrations with and without a marker chromosome. Specific biological features of the Callitrichidae, such as natural twinning and genetic chimerism impeded the clarification of the pathogenesis and prevented a reliable prognosis on the fertility of the cotton-top tamarin.

Pododermatitis in Captive and Free-Ranging Greater Flamingos (Phoenicopterus roseus).

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.

Comparison of plasma vitamin A and E, copper and zinc levels in free-ranging and captive greater flamingos (Phoenicopterus roseus) and their relation to pododermatitis.

Pododermatitis is a worldwide problem in captive flamingos. Studies in domestic poultry showed that nutrition is a possible influencing factor for pododermatitis. Vitamin A and E, copper and zinc levels were analysed in two different diets (diet 1 = in-house mix and diet 2 = commercial diet) and in plasma of captive greater flamingos fed these diets and compared to those of free-ranging greater flamingos. Results were analysed with respect to type and severity of foot lesions of the individuals from the different groups. Juvenile and subadult/adult captive flamingos on diet 1 showed various types and severities of foot lesions, whereas no foot lesions were found at the time of blood sampling in juvenile captive flamingos on diet 2. Juvenile captive flamingos on diet 1 had significantly lower plasma zinc levels than juvenile captive flamingos on diet 2 and juvenile free-ranging flamingos; data were also lower than reference ranges for flamingos, poultry and cranes. There were no significant differences in plasma vitamin A, vitamin E, copper or zinc levels between animals with different types of foot lesions or with different severity scores. Shortly after the change to diet 2 (fed to juvenile captive flamingos that did not show any foot lesion), the flooring of the outdoor water pools was covered with fine granular sand. Because both factors (nutrition and flooring) were changed during the same evaluation period, it cannot be concluded which factor contributed in what extent to the reduction of foot lesions. While it is assumed that low plasma zinc levels identified in the group of juvenile captive flamingos on diet 1 were not directly responsible for foot lesions observed in these animals, they may have played a role in altering the skin integrity of the feet and predisposing them to pododermatitis.

Influence of feeding and UVB exposition on the absorption mechanisms of calcium in the gastrointestinal tract of veiled chameleons (Chamaeleo calyptratus).

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.

Anaesthesia with medetomidine-ketamine-isoflurane with and without midazolam, in eight captive chimpanzees (Pan troglodytes) premedicated with oral zuclopenthixol.

In 8 captive adult chimpanzees of various ages premedicated with oral zuclopenthixol anaesthesia was induced intramuscularly with a combination of medetomidine and ketamine (40 or 50 µg/kg and 5 mg/kg, IM, respectively), with and without midazolam (0.05 mg/kg), and maintained with isoflurane in oxygen. At the end of the procedure, sedation was reversed with atipamezole (0.25 mg/kg, IM) and sarmazenil (0.005 mg/kg, IM) when midazolam had been administered. Oral zuclopenthixol resulted in tranquillization of the whole group and only one animal required a second dart injection to achieve adequately deep anaesthesia. Effective and reliable anaesthesia was achieved in all apes; the depth of hypnosis was stable and sudden arousal did not occur. Physiological parameters remained within normal ranges in the majority of the animals; however, manageable anaesthesia-related complications, namely apnoea after darting, hypotension, hypoventilation, hypoxemia and prolonged recovery, occurred in 6 out of 8 animals. The use of monitoring devices was essential to guarantee adequate management of these complications.

Huit chimpanzés adultes d'un zoo, d'âges différents, ont été anesthésiés, après prémédication orale au zuclopenthixol, avec une combinaison de médétomidine (40 ou 50 µg/kg, IM) et de kétamine (5 mg/kg, IM), avec ou sans ajout de midazolam. La narcose a ensuite été poursuivie par administration d'isoflurane/oxygène. A la fin de l'anesthésie, la sédation a été antagonisée avec de l'atipamézol (0.25 mg/kg, IM) et, lorsqu'on avait utilisé du midazolam, avec en outre du sarmazenil (0.005 mg/kg, IM). L'administration orale de zuclopenthixol amenait une tranquillisation du groupe entier et seul un animal a nécessité une seconde injection par sarbacane pour atteindre une profondeur de narcose suffisante. La profondeur de narcose était constante et on a constaté aucun réveil soudain. La majorité des animaux présentaient des paramètres physiologiques dans les normes mais il s'est produit diverses complications d'anesthésie, comme arrêt respiratoire peu après la télé-injection, hypotension, hypoventilation, hypoxie et réveil retardé chez 6 des 8 animaux. Les outils de surveillance utilisés s'avèrent essentiels pour une gestion adaptée des complications qui peuvent se produire.

Factors influencing the onset and progression of pododermatitis in captive flamingos (Phoenicopteridae).

Pododermatitis is a worldwide problem in captive flamingos. We performed an evaluation of different influence factors (age, sex, weight, origin, breeding status) and a comparison of foot lesions between several zoological institutions and the feet of free-ranging Greater flamingos (Phoenicopterus roseus). A scoring system was used to determine the prevalence and types of lesions and severity. Cracks and nodules developed as early as 3 months of age and papillomatous growths as early as 6 to 7 months of age in captivity. Nodules with ulceration occurred significantly more often in birds older than 31 years and heavier than 4 kg. The comparison of different institutions revealed that birds kept in enclosures with natural-floored water ponds had significantly less severe lesions than birds kept in concrete water ponds. None of the free-ranging flamingos, which live on a muddy underground, showed any lesion. This study demonstrates that flooring, weight and age are important in the onset and progression of pododermatitis in flamingos.

Les pododermatites représentent dans tout le monde un problème chez les flamants détenus en captivité. Dans la présente étude, on examine divers facteurs (âge, sexe, poids, origine, couvaison) pouvant influencer cette pathologie et on compare les lésions constatées dans diverses conditions de détention entre elles ainsi que par rapport aux pattes de flamants roses (Phoenicopterus roseus) sauvages. La prévalence et les divers types de lésions, de même que leur gravité sont déterminées sur la base d'un catalogue de critères. Des fissures et des nodules se développent déjà chez des animaux âgés de trois mois; on peut observer des proliférations papillomateuses pour la première fois vers l'âge de 6 à 7 mois. Les nodules avec ulcération centrale s'observent significativement plus souvent chez des animaux de plus de 31 ans de même que chez ceux qui pèsent plus de 4 kg. Les flamants provenant d'enclos avec des étangs au fond naturel présentent des lésions moins fréquentes et plus bénignes que ceux détenus dans des enclos avec des étangs au fond en béton. On n'a observé aucune lésion podale chez les flamants roses sauvages vivant sur un sol argileux. La présente étude démontre que le sol, le poids et l'âge jouent un rôle dans l'apparition et le développement des pododermatites chez les flamants détenus en captivité.

Dry matter and calcium digestibility in captive veiled chameleons (Chamaeleo calyptratus).

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.

Septicaemia caused by Edwardsiella tarda and Plesiomonas shigelloides in captive penguin chicks.

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.

Changes in body weight, hematology and serum chemistry in captive plains viscachas (Lagostomus maximus) with presumptive diabetes type II after a diet change.

We report body weights (BW) and blood and serum analyses for 6 fully mature and 8 not-yet-mature captive plains viscachas before and 3, 6 and 9 months after switching from a low-fiber, high-energy diet to a high-fiber, low-energy diet. Initially, body weights, serum glucose, fructosamine and cholesterol levels were above the reference range in the fully mature animals. Furthermore, 4 of these animals had bilateral cataracts. After the diet change, these parameters dropped into the reference range. However, 9 months later, a slightly increased BW became evident again. The findings are consistent with a type II diabetes mellitus and underline the importance of dietary prevention.

Concentration of 17 trace elements in serum and whole blood of plains viscachas (Lagostomus maximus) by ICP-MS, their reference ranges, and their relation to cataract.

The reference ranges of the trace elements Al, As, Be, B, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Li, Rb, Se, Sr, and Zn were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in sera of a group of free-ranging plains viscachas of the pampa grasslands of Argentina. The values were compared with those of a small group of captive plains viscachas of the Zurich Zoo with diabetes and bilateral cataracts. In addition, a method for digestion of whole-blood samples is described for the trace element determination. Significant differences in the concentration of trace elements in the two groups of animals are discussed. No correlation was found between the levels of selenium and of other trace elements compared to the formation of cataracts.

[Ferrets in veterinary practice]. / Frettchen in der Tierarztpraxis.

Ferrets (Mustela putorius furo) show up with increasing frequency in veterinary practice. Originally domesticated for hunting of rodents and rabbits, they became very popular pets which require legal permission though and the further fulfillment of various husbandry needs. Ferrets have to be maintained on a high protein diet which in practice is often done with commercial feline products. Physical examination is similar to dogs and cats whereas the frequent occurrence of non-specific symptoms require further diagnostic investigation including blood sampling, radiology, ultrasound or exploratory laparatomy. The preferred anaesthetic method is the direct face mask induction and maintenance using isoflurane without prämedication. Special attention of veterinarians has to be paid to canine distemper vaccination, the specialized reproduction physiology of the females (jills) which can develop, if unmated, a persistent oestrus with fatal consequences of hyperestrogenism, as well as the frequent occurrence of further endocrine disorders, congestive cardiomyopathy and gastrointestinal diseases.

A retrospective study of dental conditions of captive brown bears (Ursus arctos spp.) compared with free-ranging Alaskan grizzlies (Ursus arctos horribilis).

The teeth of 63 skulls of brown bears (Ursus arctos spp.) that had lived in the Bernese bear pit between 1850 and 1995 were examined and radiographed for occlusion, loss of teeth, calcified dental plaque and calculus, attrition, and caries. Dental pathology and periodontal status were evaluated with respect to age and location in the dentition. Further techniques such as computed tomography, microhardness testing, histologic sectioning, and scanning electron microscopy were used in selected cases to verify the macroscopic and radiographic diagnoses. Fourteen skulls originating from free-ranging wild Alaskan brown bears (Ursus arctos horribilis) were examined as a control group. For zoo bears over 10 yr old, severe enamel and dentinal attrition has been observed in canine teeth, with exposed pulp and proximal lesions in molar teeth. Deposits of calcified dental calculus were found in various locations and increased with age. A much lower degree of calculus deposition was found in the Alaskan grizzlies, whose average caries frequency was higher but with large individual variation and different locations in canine teeth and occlusal lesions in molar and premolar teeth. Radiographic evaluation of perialveolar osteolytic processes revealed a greater frequency of apical and combined apical-marginal lesions of the alveoli in zoo bears over 10 yr old. Stereotypical behavior like cage chewing is a suspected cause of canine tooth and secondary alveolar lesions, whereas a nutritionally inappropriate diet and inadequate opportunities for tooth-cleaning activities are responsible for the lack of natural cleaning and the extensive calculus formation that results. The methods used in this study are useful in assessing and comparing the dental health status of free-ranging bears, and those living in zoological gardens, by evaluating anesthetized bears or bear skull collections representing both groups.

Sporotrichosis in a nine-banded armadillo (Dasypus novemcinctus).

An adult female nine-banded armadillo (Dasypus novemcinctus) died in the quarantine station of a private Swiss zoo. Multifocal ulcerative skin lesions and multiple hemorrhages in the lungs were found at necropsy. The spleen was enlarged and dark red. Histologically, there was diffuse granulomatous infiltration, including multinucleated giant cells, of the skin lesions, lungs, spleen, liver, heart, and kidneys. Abundant periodic acid-Schiff-positive yeastlike cells were demonstrated intracellularly in giant cells and extracellularly scattered throughout the tissues. Morphology of the cells varied, with some nonbudding cells resembling Cryptococcus neoformans and others resembling Sporothrix schenckii. A diagnosis of sporotrichosis was confirmed by immunofluorescence studies. This is the first report of sporotrichosis in an armadillo in a zoological garden and the third report of sporotrichosis in D. novemcinctus.

Dental health status and endodontic treatment of captive brown bears (Ursus arctos ssp.) living in the Bernese bear pit.

The teeth of five adult captive brown bears (Ursus arctos ssp.) were examined and radiographed for occlusion, loss of teeth, dental plaque and calculus, and attrition under general anesthesia. Deposits of dental calculus were found in various locations with an overall prevalence of 8% to 15% of all tooth surfaces. In all five animals, severe enamel and dentinal attrition defects were observed in canine teeth with exposed pulp. Cage-chewing behavior is probably the main cause for the dental attrition. The composition of the food and feeding management are most likely responsible for the lack of natural cleaning and the resulting plaque and calculus formation. All affected canine teeth were treated with endodontic procedures using several materials and techniques, and evaluated one- to two-and-a-half years later by clinical examination, radiography, and scanning electron microscopy of silicone casts of the treated teeth. All coronal fillings were tight. The apices were not completely sealed in two teeth. We conclude that the use of adequate and specialized instrumentation and techniques for the treatment of these long, curved, large diameter root canals is more important than the particular endodontic and restorative materials used. The dental health status of zoo animals is an indicator of their general well-being. Preventive measures should be taken in their environment and management to minimize the risk of dental conditions.

[Dicrocoeliasis in New World camelids]. / Dikrozöliose bei Neuweltkameliden.

Natural infections with the lancet fluke (Dicrocoelium dendriticum) were detected in a group of seven diseased or dead/euthanized South American Camelids (five Llamas, two Alpacas) from Switzerland and Southern Germany. Clinical findings in almost all the animals revealed an acute decline of general condition followed by recumbency, decreased body temperature and a varying degree of anaemia. Concurrently, all animals showed an average to poor nutritional status. All liver enzyme activities analysed in serum biochemistry conformed to the reference values and therefore offered no diagnostic clues for this disease. Necropsy however, disclosed major alterations in the liver in the form of cirrhosis, abscesses, granulomas, and a massive infestation with D. dendriticum. The coprological investigations performed at the outset of the examinations revealed eggs of the lancet fluke in only two animals. This suggests that clinical findings alone permit at best only a provisional diagnosis. Repeated coprologic follow-ups showed that the presence of eggs of D. dendriticum can be diagnosed accurately and that clinical signs appear with an excretion rate above 1000 eggs per gram faeces (EpG). In these cases, praziquantel in a single dose of 50 mg/kg per os was given. This treatment was well tolerated and achieved a quite acceptable 90% reduction of eggs in the faeces.

Evaluation of effectiveness, safety and reliability of intramuscular medetomidine-ketamine for captive great apes.

Twenty great apes (six orangutans, eight chimpanzees and six gorillas) were anaesthetised prior to being transported for undergoing diagnostic and interventional procedures. Anaesthesia was induced with a combination of medetomidine and ketamine administered intramuscularly through a dart syringe. The onset of anaesthesia varied among apes: the mean (±sd) time from darting to recumbency was 12.13 (±1.9), 18.5 (±8.7) and 22.2 (±9.2) minutes in chimpanzees, orangutans and gorillas, respectively. The depth of anaesthesia was sufficient to allow safe removal of the animals from the enclosure, intravenous catheter placement and manipulation; however, the anaesthetic effect was short-acting (20 (±7) minutes in orangutans, 16 (±14) in gorillas, and 10 (±4) minutes in chimpanzees, respectively) and isoflurane administration was necessary in the majority of the apes to prolong the duration of anaesthesia, especially when lengthier procedures were performed. The sedative effect of medetomidine was reversed at the end of each procedure with atipamezole, and recovery was smooth and uneventful for all animals.