Andrew Routh

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.

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.

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.

RADIOGRAPHIC CARDIAC SILHOUETTE MEASUREMENT IN CAPTIVE LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII)

Abstract Cardiomyopathies have been increasingly noted in the captive population of Livingstones fruit bat (Pteropus livingstonii). The aim of this study was to produce a set of repeatable quantitative reference measurements that could be used to assess the cardiac size during radiographic examination of this species. Ventro-dorsal and lateral radiographs (n = 129) from a total of 42 individual Livingstones fruit bats were examined. The control group radiographs (n = 102) consisted of 34 healthy individuals. Radiographic measurements were taken of structures within the thorax and then converted into ratios. These ratios from radiographs (n = 27) were also calculated for eight individuals with diagnosed cardiomyopathy. Vertebral Heart Scores (VHS) were calculated from right lateral radiographs and compared between the two groups. From all the data, only the width of the cardiac silhouette to the width of the thorax (the W : T ratio) in the ventro-dorsal view and the VHS were found to be significantly different between both groups (P < 0.05). The group with cardiomyopathies had a mean W : T ratio of 0.59 (±0.005) and a VHS of 9.77 (±0.89), while a mean W : T ratio of 0.54 (±0.004) and a VHS of 8.71 (±0.93) was established for healthy specimens.

HEMATOLOGY AND PLASMA CHEMISTRY OF THE PLOUGHSHARE TORTOISE (ASTROCHELYS YNIPHORA) IN A CAPTIVE BREEDING PROGRAM

Abstract Blood samples from 172 captive and 40 wild, healthy, juvenile and adult, ploughshare tortoises (Astrochelys yniphora) were analyzed to determine hematological and biochemical reference intervals. Hematological analytes included packed cell volume (PCV), white blood cell count (WBC), and WBC differential estimates. Biochemical analysis included total protein measured by photometry (TP) and by refractometry (TPr), albumin (ALB), creatine kinase (CK), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), bile acids (BA), calcium (Ca), phosphorus (P), urea (UREA), and uric acid (UA). The jugular vein was identified as the preferred venipuncture site as subcarapacial vein venipuncture resulted in regular hemodilution. In due consideration of small sample sizes in some of the groups studied, adult tortoises had significantly higher plasma GLDH activity and TPr, TP, ALB, BA, and UREA concentrations and significantly lower AST activity and P concentration than juveniles. Captivity had a significant influence in some reference intervals, with captive adults presenting significantly higher WBC, and estimated counts of all white cell types as well as UREA and TPr than wild counterparts. Captive juveniles also showed significantly higher estimated monocyte and lower estimated eosinophil and basophil counts. Although these differences most likely reflect local environmental or dietary differences, without representing pathology or a deviation from the normal, they question the applicability of reference values from captive animals to wild animals and vice versa. Significant sex differences were only observed for PCV and UA. The reported reference intervals may serve as benchmarks for clinical assessment and conservation of this critically endangered species.

DIAGNOSIS AND MANAGEMENT OF BENIGN PROSTATIC HYPERPLASIA IN A PIED TAMARIN (SAGUINUS BICOLOR)

Abstract An intact male pied tamarin (Saguinus bicolor) presented with a hunched posture while moving, dysuria, pollakiuria, and hematuria. After diagnostic imaging assessment and prostate biopsy, benign prostatic hyperplasia was diagnosed. Treatments with delmadinone acetate and osaterone caused clinical signs and hematuria to resolve temporarily for a variable period of time. Because of frequent recurrence, elective surgical castration was performed, leading to resolution of the clinical signs.

FEMORAL HEAD RESECTION IN TWO LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII)

Abstract Two Livingstones fruit bats (Pteropus livingstonii) presented with a unilateral partial paresis of the hind limbs. Radiographs revealed luxation of the coxofemoral joint and degenerative joint disease in the right coxofemoral joint in one case. The second case presented with recurrent luxation of the coxofemoral joint with osteoarthrosis of the femoral head. Clinical findings in both cases led to a decision to perform a femoral head resection. The performed surgery led to the recovery of normal function of the limb without any complications in both cases.

DETOMIDINE AND BUTORPHANOL FOR STANDING SEDATION IN A RANGE OF ZOO-KEPT UNGULATE SPECIES

Abstract General anesthesia poses risks for larger zoo species, like cardiorespiratory depression, myopathy, and hyperthermia. In ruminants, ruminal bloat and regurgitation of rumen contents with potential aspiration pneumonia are added risks. Thus, the use of sedation to perform minor procedures is justified in zoo animals. A combination of detomidine and butorphanol has been routinely used in domestic animals. This drug combination, administered by remote intramuscular injection, can also be applied for standing sedation in a range of zoo animals, allowing a number of minor procedures. The combination was successfully administered in five species of nondomesticated equids (Przewalski horse [Equus ferus przewalskii; n = 1], onager [Equus hemionus onager; n = 4], kiang [Equus kiang; n = 3], Grevys zebra [Equus grevyi; n = 4], and Somali wild ass [Equus africanus somaliensis; n = 7]), with a mean dose range of 0.10–0.17 mg/kg detomidine and 0.07–0.13 mg/kg butorphanol; the white (Ceratotherium simum simum; n = 12) and greater one-horned rhinoceros (Rhinoceros unicornis; n = 4), with a mean dose of 0.015 mg/kg of both detomidine and butorphanol; and Asiatic elephant bulls (Elephas maximus; n = 2), with a mean dose of 0.018 mg/kg of both detomidine and butorphanol. In addition, the combination was successfully used for standing sedation in six species of artiodactylids: giraffe (Giraffa camelopardalis reticulata; n = 3), western bongo (Tragelaphus eurycerus eurycerus; n = 2), wisent (Bison bonasus; n = 5), yak (Bos grunniens; n = 1), water buffalo (Bubalus bubalis; n = 4) and Bactrian camel (Camelus bactrianus; n = 5). The mean dose range for artiodactylid species except bongo was 0.04–0.06 mg/kg detomidine and 0.03–0.06 mg/kg butorphanol. The dose in bongo, 0.15–0.20 mg/kg detomidine and 0.13–0.15 mg/kg butorphanol, was considerably higher. Times to first effect, approach, and recovery after antidote were short. The use of detomidine and butorphanol has been demonstrated to be a reliable, safe alternative to general anesthesia for a number of large ungulate species.

SEVOFLURANE ANESTHESIA IN LIVINGSTONE'S FRUIT BATS (PTEROPUS LIVINGSTONII)

Abstract Fourteen captive Livingstones fruit bats (Pteropus livingstonii) were anesthetized for routine veterinary health checks, including echocardiography, using sevoflurane. In addition, three specimens suffering from cardiac disease and a pregnant specimen were anesthetized for clinical assessment. No anesthetic complications were observed in any of the specimens. Significant differences in the core body temperature were found between the esophageal and rectal measurements. A significant decrease in blood glucose was noted through the anesthesia, suspected to be related to an extended fasting period prior to the procedure.