Tim Bouts

Ultrasonographic Anatomy of the Asian Elephant (Elephas maximus) Eye

Abstract Bilateral transpalpebral ultrasonography was performed on 53 captive Asian elephants (Elephas maximus) in order to describe the normal ultrasonographic appearance and measurements of the Asian elephant eye. Transpalpebral ultrasonography was performed using a portable ultrasound unit and a 4–7-MHz broadband curvilinear transducer on animals housed at seven institutions in the United Kingdom and in Sri Lanka. Both males and females were included in the study and ages ranged from 14 mo to 65 yr. Ultrasonic examinations were conducted on unsedated animals, without the use of topical or local anesthesia. The ultrasonographic appearance of the globe and intraocular structures of the Asian elephant eye is similar to that in other species. Biometry measurements recorded for adult (n  =  41) and juvenile (n  =  10) Asian elephants were: axial length, 3.44 ± 0.21 cm and 3.18 ± 0.19 cm (mean ± SD); equatorial diameter, 3.88 ± 0.32 cm and 3.60 ± 0.24 cm; corneal thickness, 0.17 ± 0.02 cm and 0.16 ± 0.02 cm; anterior segment depth, 0.45 ± 0.08 cm and 0.36 ± 0.07 cm; lens diameter, 1.90 ± 0.14 cm and 1.75 ± 0.19 cm; lens depth, 1.01 ± 0.12 cm and 0.94 ± 0.10 cm, and posterior segment depth, 1.82 ± 0.17 cm and 1.72 ± 0.15 cm, respectively. Multiple linear regression analysis indicated a significant relationship between the explanatory variables (age, sex, and height) and the dependent variables (axial length, equatorial diameter, corneal thickness, anterior segment depth, lens diameter, and lens depth). The main finding of this statistical test was that the globe increases in size as the animal ages. Transpalpebral ultrasonography was found to be an effective and practical imaging modality in the evaluation of the Asian elephant eye, without the need for chemical restraint.

Positive Skin and Serologic Test Results of Diagnostic Assays for Bovine Tuberculosis and Subsequent Isolation of Mycobacterium interjectum in a Pygmy Hippopotamus (Hexaprotodon liberiensis)

Abstract A 20-yr-old male pygmy hippopotamus (Hexaprotodon liberiensis), weighing 250 kg, arrived at Zoological Society London Whipsnade Zoo (United Kingdom) from a captive collection in Portugal. A quarantine health check was performed including a comparative intradermal tuberculosis (IDTB) test. Assessment of the comparative IDTB test at 72 hr revealed a strong positive reaction at the bovine site. Serum was tested with a rapid immunochromatographic assay (TB STAT-PAK®) and was positive for tuberculosis antibodies. The tuberculosis tests were repeated 6 wk later with the same positive test outcome. In addition, a broncho-alveolar lavage (BAL) was submitted for mycobacterial culture. The positive IDTB test and TB STAT-PAK® results were supported by multiantigen print immunoassay (MAPIA). Based on these results, the animal was suspected to be infected with Mycobacterium tuberculosis complex organisms and was euthanized. No gross or histologic signs of tuberculosis were found at postmortem examination. Mycobacterium interjectum was cultured from the BAL but not from necropsy samples. The antigens used in the TB STAT-PAK® and MAPIA tests are reportedly specific for the M. tuberculosis complex, and so it is possible this animal presented with a latent case of tuberculosis or had a previous tuberculosis infection that resolved prior to testing. Cross-reactions with nontuberculous mycobacteria have been described with TB STAT-PAK® and MAPIA tests. However, Western blotting analysis using serum from this animal did not recognize M. interjectum proteins of equivalent size to the M. tuberculosis-Mycobacterium bovis proteins recognized in the MAPIA. Thus, antigenic cross-reactivity with M. interjectum can be deemed less likely, but other nontuberculous mycobacterial proteins cannot be ruled out. It is therefore possible that false-positive reactions were obtained. These results highlight the difficulty of diagnosing tuberculosis in the absence of pathology and the presence of nontuberculous mycobacteria.

Evaluation of Medetomidine-Alfaxalone and Medetomidine-Ketamine in Semi-Free Ranging Bennett's Wallabies (Macropus rufogriseus)

Abstract: Twenty-six adult semi–free-ranging Bennetts wallabies were anesthetized. Animals in group MA received medetomidine 0.1 mg/kg and alfaxalone 4 mg/kg i.m. in a 5-ml dart, whereas those in group MK received medetomidine 0.1 mg/kg and ketamine 5 mg/kg i.m. in a 3-ml dart. Dosages were based on estimated body weights. The wallabies were allowed to recover spontaneously or, if still nonresponsive at the end of the procedure, were given atipamezole 0.5 mg/kg (half the dose via i.m. and the other half via i.v.). Heart rate and respiratory rate were monitored at 5-min intervals, temperature at 10-min intervals, and two arterial blood samples were taken for blood gas analysis. Statistical analysis was performed by using analysis of variance (P < 0.05). The use of 5-ml darts in group MA compared with 3-ml darts in group MK could potentially increase the risk of iatrogenic trauma and should be considered. Induction and maintenance of anesthesia were satisfactory in both groups. There were no significant differences between the groups in mean time to first effect, recumbency, and approach, or to time to sternal recumbency and standing after reversal with atipamezole. Although bradycardia was present in both groups, no statistical differences were calculated for respiratory rate and heart rate, whereas the mean cloacal temperature was significantly lower in group MA (P = 0.01). Mixed acid-base disturbances occurred in both groups. All but one animal in group MK needed atipamezole at the end of the procedure. No adverse effects were observed after recovery.

Collection and preservation of pygmy hippopotamus (Choeropsis liberiensis) semen.

Knowledge about the reproduction of the endangered pygmy hippopotamus is almost non-existent. This study takes the first step toward changing this by devising a protocol for the collection, evaluation, and short-term preservation of semen of this endangered species. Semen was collected successfully from seven bulls by electroejaculation, using a specially designed rectal probe. Mean +/- SEM values of native sperm parameters from combined best fractions were: motility-80.0 +/- 4.1%, concentration-2421 +/- 1530 x 10(6) cells/mL, total collected cell number-759 +/- 261 x 10(6) cells, intact acrosome-87.8 +/- 1.2%, intact morphology-52.7 +/- 4.3%, and, for some, hypoosmotic swelling test-79.3 +/- 4.4% and seminal plasma osmolarity-297.5 +/- 3.3 mOsm. Seven different extenders were tested for sperm storage under chilling conditions: Berliner Cryomedium (BC), Biladyl, modification of Kenney modified Tyrodes medium (KMT), MES medium, Androhep((R)), boar M III() extender and Human Sperm Refrigeration Medium. While differences between males were apparent, the BC was consistently superior to all other extenders in sperm motility and facilitated storage for 7 d with up to 30% motility and some motility even after 3 weeks. With this knowledge in hand, the obvious two directions for future research are to conduct artificial insemination and to develop a technique for sperm cryopreservation.

Comparison of three anaesthetic protocols in Bennett's wallabies (Macropus rufogriseus)

OBJECTIVE Investigate physiological and sedative/anaesthetic effects of xylazine, medetomidine or dexmedetomidine combined with ketamine in free-ranging Bennetts wallabies. STUDY DESIGN Prospective clinical trial. ANIMALS Twenty-six adult free-ranging Bennetts wallabies. METHODS Animals were darted intramuscularly with one of three treatments: xylazine and ketamine, 2.0 and 15.0 mg kg(-1), respectively (XK): medetomidine and ketamine 0.1 and 5.0 mg kg(-1) (MK) and dexmedetomidine and ketamine 0.05 and 5.0 mg kg(-1) (DMK). Body weights were estimated. If the animal was still laterally recumbent after 45 minutes of anaesthesia, then an alpha-2 adrenoceptor antagonist, atipamezole, was administered (XK: 0.4 mg kg(-1), MK: 5 mg kg(-1), DMK: 2.5 mg kg(-1)). Heart rate (HR) and respiratory rate (f(R)) were recorded at 5-minute intervals and temperature at 10-minute intervals. Venous blood was taken 30 minutes after initial injection. Statistical analysis utilized anova. p < 0.05 was considered significant. RESULTS Animals became recumbent rapidly in all groups. XK animals had muscle twitches, responded to external stimuli, and three animals required additional dosing; this was not observed in the MK and DMK groups. HR (mean +/- SD beats minute(-1)) in XK (81 +/- 4) was significantly higher than MK (74 +/- 2) and DMK (67 +/- 4). There were no differences in f(R), temperature, blood-gas and biochemical values between groups. More animals in MK (9/10) and DMK (5/6) needed antagonism of anaesthesia compared with XK (1/10). There were no adverse effects after anaesthesia. CONCLUSION AND CLINICAL RELEVANCE Cardio-respiratory effects were similar in all groups. There were fewer muscle twitches and reactions to external stimuli in MK and DMK. Duration of anaesthesia was shorter in XK; most animals in MK and DMK needed atipamezole to assist recovery. All three treatments provided satisfactory sedation/anaesthesia and are suitable for use in Bennetts wallabies.

Spinal cord injury during recovery from anaesthesia in a giraffe

ANAESTHESIA of giraffes carries particular risks of morbidity and mortality as a result of the physical characteristics of a large, long-legged, long-necked animal with a heavy head; death is reported in approximately one in 10 cases (Benbow and Lyon 2001, Bush and others 2002, Flach and others 2002). Mortality may relate to physical damage or occasionally regurgitation and aspiration (Citino and Bush 2007). This short communication describes an accident during recovery of a giraffe from an otherwise straightforward anaesthetic. A 10-year-old reticulated giraffe bull (estimated weight 1000 kg) was anaesthetised for treatment of overgrown and misshapen hooves. Food was withheld for 18 hours and water for 12 hours before the procedure. The giraffe house was prepared by covering the walls with small straw bales, and bedding was allowed to accumulate over several days as deep litter. Haloperidol (20 mg) (Serenace; Baker Norton) was administered intramuscularly by remote injection (JM Special Rifle; Dan-Inject). One hour later, 50 mg medetomidine (Zalopine; Orion) was administered intramuscularly by dart, followed by 2000 mg ketamine (ketamine dry; Parke Davis), administered by the same route once sedation had developed. The giraffe became recumbent 10 minutes after the administration of ketamine, and a further dose of 500 mg ketamine was injected intravenously to allow tracheal intubation using manual palpation (25 mm cuffed endotracheal tube). …

Evaluation of medetomidine-ketamine and dexmedetomidine-ketamine in Chinese water deer (Hydropotes inermis)

OBJECTIVE To investigate physiological and sedative/immobilization effects of medetomidine or dexmedetomidine combined with ketamine in free-ranging Chinese water deer (CWD). STUDY DESIGN Prospective clinical trial. ANIMALS 10 free-ranging adult Chinese water deer (11.0±2.6 kg). METHODS Animals were darted intramuscularly with 0.08±0.004 mg kg(-1) medetomidine and 3.2±0.2 mg kg(-1) ketamine (MK) or 0.04±0.01 mg kg(-1) dexmedetomidine and 2.9±0.1 mg kg(-1) ketamine (DMK). If the animal was still laterally recumbent after 60 minutes of immobilization, atipamezole was administered intravenously (MK: 0.4±0.02 mg kg(-1), DMK: 0.2±0.03 mg kg(-1)). Heart rate (HR) respiratory rate (f(R)) and temperature were recorded at 5-minute intervals. Arterial blood was taken 15 and 45 minutes after initial injection. Statistical analysis was performed using Students t-test or ANOVA. p<0.05 was considered significant. RESULTS Animals became recumbent rapidly in both groups. Most had involuntary ear twitches, but there was no response to external stimuli. There were no statistical differences in mean HR (MK: 75±14 beats minute(-1); DMK: 85±21 beats minute(-1)), f(R) (MK: 51±35 breaths minute(-1); DMK; 36±9 breaths minute(-1)), temperature (MK: 38.1±0.7 °C; DMK: 38.4±0.5 °C), blood gas values (MK: PaO(2) 63±6 mmHg, PaCO(2) 49.6±2.6 mmHg, HCO(3)(-) 30.8±4.5 mmol L(-1); DMK: PaO(2) 77±35 mmHg, PaCO(2) 45.9±11.5 mmHg, HCO(3)(-) 31.0±4.5 mmol L(-1)) and biochemical values between groups but temperature decreased in both groups. All animals needed antagonism of immobilization after 60 minutes. Recovery was quick and uneventful. There were no adverse effects after recovery. CONCLUSION AND CLINICAL RELEVANCE Both anaesthetic protocols provided satisfactory immobilisation. There was no clear preference for either protocol and both appear suitable for CWD.

Propagation Method of Saving Valuable Strains from a Mycobacterium liflandii Infection in Western Clawed Frogs (Silurana tropicalis)

Abstract:  Mycobacterium liflandii has been responsible for an emerging infection reported in the international trade of Western clawed frogs (Silurana tropicalis). This study shows that this mycolactone-producing Mycobacterium (MPM) has expanded its distribution range to France. The results of this study suggest that the use of in vitro fertilization to maintain genetic lines could be a temporary solution for valuable S. tropicalis propagation.

Thoracic radiography of healthy captive male and female Squirrel monkey (Saimiri spp.)

The purpose of this prospective study was to describe the normal anatomy and provide reference ranges for measurements of thoracic radiography on Squirrel monkeys (n = 13). Thoracic radiography is a common non-invasive diagnostic tool for both cardiac and non-cardiac thoracic structures. Furthermore cardiac disease is a common condition in captive primates. In this study, left-right lateral, right-left lateral and dorsoventral projections of 13 healthy Squirrel monkeys were reviewed during their annual health examinations. The mean Vertebral Heart Score on the left-right and right-left lateral projections were 8,98 ± 0,25 and 8,85 ± 0,35 respectively. The cardio-thoracic ratio on the dorsoventral projection was 0,68 ± 0,03. The trachea to inlet ratio was 0,33 ± 0,04. Other measurements are provided for the skeletal, cardiac and respiratory systems. Knowledge of the normal radiographic thoracic anatomy is fundamental in clinical as well as research settings for accurate diagnosis of diseases.

Urinary specific gravity as an alternative for the normalisation of endocrine metabolite concentrations in giant panda (Ailuropoda melanoleuca) reproductive monitoring

Reproductive monitoring for captive breeding in giant pandas is based on behavioural observation and non-invasive hormone analysis. In urine, interpretation of results requires normalisation due to an animal’s changing hydration. Correction of urinary concentrations based on creatinine is the gold standard. In this study, a largely unexplored, easy-to-perform normalisation technique, based on urinary specific gravity (USpG), was examined and compared to creatinine. To this extent, six cycles from two female pandas (SB741(1) and SB569(5)) were monitored through urine analysis for oestrogen, progesterone, ceruloplasmin and 13,14-dihydro-15-keto-PGF2a (PGFM). The Pearson’s correlation between creatinine and USpG was high (r = 0.805–0.894; p < 0.01), indicative for a similar performance of both normalisation methods. However, generally lower values were observed during pro-oestrus and primary (progesterone) rise. This could be associated with huge shifts in appetite, monitored by faecal output (kg) with an averaged > 50% decrease during oestrus and >50% increase during primary progesterone rise. In parallel, respectively highest and lowest creatinine and USpG levels, were measured, with creatinine obviously more affected as a result of linkage with muscle tissue metabolism affected by reproductive hormones. As a consequence, metabolite levels were significantly different between both corrected datasets with significantly higher oestrogen peak levels during oestrus ranging from 2.13–86.93 and 31.61–306.45 ng/mL (USpG correction) versus 2.33–31.20 and 36.36–249.05 ng/mL Cr (creatinine correction) for SB569 and SB741 respectively, and significant lower progesterone levels during primary progesterone rise ranging from 0.35–3.21 and 0.85–6.80 ng/mL (USpG correction) versus 0.52–10.31 and 2.10–272.74 ng/mL Cr (creatinine correction) for SB569 and SB741 respectively. Consequently, USpG correction rendered unbiased profiles, less subject to variation and metabolic artefacts and therefore allowed a more straightforward identification of peak oestrogen and onset of secondary progesterone rise, being potentially advantageous for future studies unravelling key giant panda reproductive events, including (delayed) implantation. The alternative application of USpG as a normalisation factor was further supported by its easy application and environmental and technical robustness.