Jessica L. Siegal-Willott

MICROCHIP-ASSOCIATED LEIOMYOSARCOMA IN AN EGYPTIAN FRUIT BAT (ROUSETTUS AEGYPTIACUS)

Abstract Microchips are commonly used in companion, research, and zoo animal medicine for easy, reliable, and cost-effective identification with relatively low risk of side effects. This report describes development of a metastatic leiomyosarcoma associated with a microchip in an Egyptian fruit bat (Rousettus aegyptiacus).

BUTORPHANOL, AZAPERONE, AND MEDETOMIDINE ANESTHESIA IN FREE-RANGING WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) USING RADIOTRANSMITTER DARTS

Fourteen free-ranging white-tailed deer (Odocoileus virginianus) were successfully anesthetized for a total of 15 anesthetic events using a combination of butorphanol (mean±SD, 0.58±0.1 mg/kg), azaperone (0.37±0.06 mg/kg), and medetomidine (0.19±0.03 mg/kg) (BAM) administered by radiotelemetry darts from hunting blinds between November 2006 and May 2007. Mean time to locate deer (mean±SD, 17. 3±7 min), to recumbency (21.4±5 min), to initiation of data acquisition (27.5±8 min), total down time (37±6 min), and average distance run (161±82 m) were recorded. Physiologic monitoring was done every 5 min for a total of 20 min. Arterial blood gases were collected every 10 min. Mild to moderate hypoxemia and mildly depressed ventilation occurred in some animals. Muscle relaxation and plane of anesthesia were adequate for completion of all procedures; two deer were administered intravenous butorphanol supplementation to achieve light anesthesia (mean±SD, 0.19 mg/kg; 0.12 mg/kg). Recovery following intramuscular administration of naltrexone (1.34±0.42 mg/kg; 2× butorphanol dose) and atipamezole (0.93±0.14 mg/kg; 5× medetomidine dose) was rapid, smooth, and complete. Mean±SD recovery time was 4.5±1.5 min. Overall efficacy of the Pneu-Dart radiotelemetry system was 65%. Negative attributes of this protocol included long induction time and dart failure. No known mortalities occurred as a result of the study. This drug combination provided safe, reliable, short-term anesthesia of free-ranging white-tailed deer. Further evaluation for use in field procedures in other cervids is warranted.

Proximate Nutrient Analyses of Four Species of Submerged Aquatic Vegetation Consumed by Florida Manatee (Trichechus manatus latirostris) Compared to Romaine Lettuce (Lactuca sativa var. longifolia)

Abstract Free-ranging Florida manatees (Trichechus manatus latirostris) consume a variety of sea grasses and algae. This study compared the dry matter (DM) content, proximate nutrients (crude protein [CP], ether-extracted crude fat [EE], nonfiber carbohydrate [NFC], and ash), and the calculated digestible energy (DE) of sea grasses (Thalassia testudinum, Halodule wrightii, and Syringodium filiforme) collected in spring, summer, and winter, and an alga (Chara sp.) with those of romaine lettuce (Lactuca sativa var. longifolia). Neutral-detergent fiber (NDF), acid-detergent fiber (ADF), and lignin (L) measured after ash-extraction were also compared. Results of statistical tests (α  =  0.01) revealed DM content was higher in aquatic vegetation than in lettuce (P  =  0.0001), but NDF and ADF were up to threefold greater, EE (P  =  0.00001) and CP (P  =  0.00001) were 2–9 times less, and NFC (P  =  0.0001) was 2–6 times lower in sea grass than in lettuce, on a DM basis. Chara was lower in NDF, ADF, L, EE, CP, and NFC relative to lettuce on a DM basis. Ash content (DM basis) was higher (P  =  0.0001), and DE was 2–6 times lower in aquatic vegetation than in lettuce. Sea grass rhizomes had lower L and higher ash contents (DM basis) than sea grass leaves. Based on the nutrient analyses, romaine lettuce and sea grasses are not equivalent forages, which suggests that the current diet of captive Florida manatees should be reassessed.

Cardiac Evaluation of Clinically Healthy Captive Maned Wolves (Chrysocyon brachyurus)

Abstract The objective of this project was to determine radiographic vertebral heart sizes and electrocardiographic (ECG) and echocardiographic measurements in healthy anesthetized maned wolves (Chrysocyon brachyurus). The wolves, housed at the White Oak Conservation and Smithsonian National Zoo Conservation and Research Centers, were being anesthetized for annual examinations. Cardiac auscultation, thoracic radiographs, a standard 6-lead ECG, and echocardiography were performed on the wolves while they were under general anesthesia. Thirteen maned wolves were evaluated: five males and eight females. Mean age was 6.4 ± 4.4 years (range, 2–13 years). Mean weight was 26 ± 2.95 kg (range, 22–32 kg). Low-grade systolic murmurs were auscultated in three of 13 maned wolves. Evaluation of ECGs revealed a sinus rhythm, with a QRS morphology, and mean electrical axis similar to domestic canines. Radiographic evaluation revealed a mean vertebral heart size of 8.27 ± 0.48 (range, 7.9–8.6). In addition, the cardiac silhouette was seen to elongate, with an increase in sternal contact in older wolves. Echocardiography showed that mitral valve degenerative changes and insufficiency is likely common in older wolves. Visualization of physiologic regurgitation across the mitral and pulmonary valves was common in wolves of all ages. Left ventricular measurements were similar to those reported for healthy dogs, and several variables correlated well with body weight. Two wolves were found to have one to three heartworms in the right pulmonary artery, and degenerative mitral valve disease was determined in maned wolves older than 6 years of age. All of the wolves in this study were on heartworm preventative and tested negative for heartworm antigen at their annual examinations. The results of this study provide reference information for use in the cardiac evaluation of anesthetized maned wolves.

ELECTROCARDIOGRAPHY IN TWO SUBSPECIES OF MANATEE (TRICHECHUS MANATUS LATIROSTRIS AND T. M. MANATUS)

Abstract Electrocardiographic (ECG) measurements were recorded in two subspecies of awake, apparently healthy, wild manatees (Trichechus manatus latirostris and T. m. manatus) undergoing routine field examinations in Florida and Belize. Six unsedated juveniles (dependent and independent calves) and 6 adults were restrained in ventral recumbency for ECG measurements. Six lead ECGs were recorded for all manatees and the following parameters were determined: heart rate and rhythm; P, QRS, and T wave morphology, amplitude, and duration; and mean electrical axis (MEA). Statistical differences using a t-test for equality of means were determined. No statistical difference was seen based on sex or subspecies of manatees in the above measured criteria. Statistical differences existed in heart rate (P = 0.047), P wave duration (P = 0.019), PR interval (P = 0.025), and MEA (P = 0.021) between adult manatees and calves. Our findings revealed normal sinus rhythms, no detectable arrhythmias, prolonged PR and QT intervals, prolonged P wave duration, and small R wave amplitude as compared with cetacea and other marine mammals. This paper documents the techniques for and baseline recordings of ECGs in juvenile and adult free-living manatees. It also demonstrates that continual assessment of cardiac electrical activity in the awake manatee can be completed and can be used to aid veterinarians and biologists in routine health assessment, during procedures, and in detecting the presence of cardiac disease or dysfunction.

Encephalitis Caused by Sarcocystis falcatula-like Organisms in a White Cockatoo (Cacatua alba)

Abstract A 23-year-old white cockatoo (Cacatua alba) was examined because of severe muscle wasting and acute onset of ataxia and right head tilt. Results of diagnostic tests were inconclusive, and the bird died despite supportive care and empirical treatment. Results of necropsy and histopathologic examination revealed cysts within skeletal and cardiac muscle, meronts (schizonts) within cerebellar tissue, and encephalitis caused by infection with Sarcocystis falcatula-like organisms.

Distal Limb Radiography, Ossification, and Growth Plate Closure in the Juvenile Asian Elephant (Elephas maximus)

Abstract Eleven juvenile Asian elephants (Elephas maximus) were evaluated radiographically to determine the relative times of growth plate closure and phalangeal ossification in the bones of the distal forelimb. Specifically, the first, second, and third phalanges of the third digit (D3) were evaluated, as well as the third phalanx of digits 1, 2, 4, and 5. All elephants were healthy at the time of examination. A retrospective evaluation of radiographs from six of the 11 juvenile elephants was also completed to augment the data set. This study reports the methods used to obtain high-quality radiographs of the distal juvenile elephant limb, ossification characteristics of the phalanges, relative times of growth plate closure within the proximal phalanges of D3, and a method for age estimation based on radiographic findings. This study will help clinicians in conducting elephant foot radiography, in evaluating foot radiographs in juvenile elephants, in recognizing normal versus pathologic change, and in estimating juvenile elephant age based on radiographic ossification characteristics and growth plate closure times. Consistent use of the proposed foot radiograph technique is recommended to facilitate foot disease recognition and as part of the annual examination of captive Asian elephants.

Lack of Detectable Antibody Response in Greater Flamingos (Phoenicopterus ruber ruber) After Vaccination Against West Nile Virus With a Killed Equine Vaccine

Abstract Greater flamingos (Phoenicopterus ruber ruber), an endangered and popular zoo bird species, are susceptible to West Nile virus (WNV) infection, often with a fatal outcome. To determine whether vaccination of greater flamingos produced an immunologic response with measurable antibody titers and to monitor for adverse effects of vaccination on health status, a vaccine trial against WNV infection, using a killed vaccine licensed for use in horses, was performed in 1-month-old flamingo chicks. Fifteen chicks determined to be seronegative for WNV were divided into 2 groups: Group A (n = 8) received 2, 1-ml IM doses of vaccine 3 weeks apart; and Group B (n = 7) received 1, 0.5-ml IM dose, followed by 2, 1-ml IM doses, all given 3 weeks apart. A booster vaccination of 1 ml was administered to all birds 280 days after the initial vaccination series. Antibody titers were measured after the initial immunization and before and 3 weeks after the booster vaccination by plaque-reduction neutralization testing (PRNT). A positive titer at the 90% plaque-reduction cut-off was not detected after initial vaccination or booster vaccination in any of the birds studied, but serum neutralizing activity was detected in 60% of the samples after the booster at 50%–82% plaque reduction at a 1:20 dilution. No adverse effects of vaccination were observed. The lack of a demonstrable antibody response to WNV vaccination in the flamingos may be attributable to the lack of species specificity of the vaccine, poorly developed immune system in 1-month-old flamingo chicks, poor sample handling or storage, or inadequate vaccine dose volume or frequency of administration.

Monitoring oral temperature, heart rate, and respiration rate of West Indian manatees (Trichechus manatus) during capture and handling in the field

West Indian manatees (Trichechus manatus) are captured, handled, and transported to facilitate conservation, research, and rehabilitation efforts. Monitoring manatee oral temperature (OT), heart rate (HR), and respiration rate (RR) during outof-water handling can assist efforts to maintain animal well-being and improve medical response to evidence of declining health. To determine effects of capture on manatee vital signs, we monitored OT, HR, and RR continuously for a 50-min period in 38 healthy, awake, juvenile and adult Florida manatees (T. m. latirostris) and 48 similar Antillean manatees (T. m. manatus). We examined creatine kinase (CK), potassium (K

EVALUATION OF CAPTIVE GIBBONS (HYLOBATES SPP., NOMASCUS SPP., SYMPHALANGUS SPP.) IN NORTH AMERICAN ZOOLOGICAL INSTITUTIONS FOR GIBBON APE LEUKEMIA VIRUS (GALV)

Abstract:  This study evaluated 79 captive gibbons (Hylobates, Nomascus, and Symphalangus spp.) within 30 North American zoological institutions for evidence of exposure to and possible infection with gibbon ape leukemia virus (GALV). Enzyme-linked immunosorbent assays (ELISAs) on gibbon serum samples revealed the presence of antibodies against GALV antigens in 28% of animals, indicating previous exposure or possibly protective immunity to GALV. Virus detection in gibbon blood or serum using polymerase chain reaction (PCR) or co-culture of gibbon peripheral blood mononuclear cells with human cells was negative for all samples submitted. The majority (19/27, 70%) of animals with reported health conditions were clinically healthy at the time of sample collection. Historically accrued clinical data were used to assess association of diseases in gibbons antibody positive for GALV. The results suggest captive gibbons could mount an immune response to GALV and show no evidence of infection. There was no association with neoplastic conditions in seropositive animals. The potential role of gibbons as a reservoir for GALV and the role of GALV as an epizoonotic-zoonotic agent or as a contributor to gibbon ape morbidity and mortality are not substantiated by the study findings.