Ellen Wiedner

KINETICS OF VIRAL LOADS AND GENOTYPIC ANALYSIS OF ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS-1 INFECTION IN CAPTIVE ASIAN ELEPHANTS (ELEPHAS MAXIMUS)

Abstract:  Elephant endotheliotropic herpesviruses (EEHVs) can cause fatal hemorrhagic disease in juvenile Asian elephants (Elephas maximus); however, sporadic shedding of virus in trunk washes collected from healthy elephants also has been detected. Data regarding the relationship of viral loads in blood compared with trunk washes are lacking, and questions about whether elephants can undergo multiple infections with EEHVs have not been addressed previously. Real-time quantitative polymerase chain reaction was used to determine the kinetics of EEHV1 loads, and genotypic analysis was performed on EEHV1 DNA detected in various fluid samples obtained from five Asian elephants that survived detectable EEHV1 DNAemia on at least two separate occasions. In three elephants displaying clinical signs of illness, preclinical EEHV1 DNAemia was detectable, and peak whole-blood viral loads occurred 3–8 days after the onset of clinical signs. In two elephants with EEHV1 DNAemia that persisted for 7–21 days, no clinical signs of illness were observed. Detection of EEHV1 DNA in trunk washes peaked approximately 21 days after DNAemia, and viral genotypes detected during DNAemia matched those detected in subsequent trunk washes from the same elephant. In each of the five elephants, two distinct EEHV1 genotypes were identified in whole blood and trunk washes at different time points. In each case, these genotypes represented both an EEHV1A and an EEHV1B subtype. These data suggest that knowledge of viral loads could be useful for the management of elephants before or during clinical illness. Furthermore, sequential infection with both EEHV1 subtypes occurs in Asian elephants, suggesting that they do not elicit cross-protective sterilizing immunity. These data will be useful to individuals involved in the husbandry and clinical care of Asian elephants.

PERICARDIAL MESOTHELIOMA IN A BENGAL TIGER (PANTHERA TIGRIS)

Abstract A 17-year-old Bengal tiger (Panthera tigris) presented with dyspnea and tachypnea. Radiographs revealed severe pleural and pericardial effusion, but no obvious mass. During attempts to remove the fluid under anesthesia, the cat developed cardiac tamponade and died. At necropsy, a nodular mass was found at the heart base and was identified as a pericardial mesothelioma. This is the first report of this tumor in any large cat.

Electrocardiography of the Asian Elephant (Elephas maximus)

Abstract Electrocardiograms (ECGs) are infrequently performed on Asian elephants (Elephas maximus), and few studies have been reported in the literature. The aim of this study was to determine reference ranges of ECG parameters in Asian elephants and to ascertain if age, body weight, and position of the elephant significantly affected the ECG. Electrocardiograms were obtained from 27 captive, nonsedated apparently healthy Asian elephants while they were standing (ST), in right lateral recumbency (RL), and/or in left lateral recumbency (LL). Six-lead ECGs were obtained using novel clamps and long ECG cables (71 cm). From lead I, standard waveforms and intervals were analyzed, including PR interval, QT interval, ST segment, P, QRS, T, and U waves if they were present. One animal was determined to have a previously undiagnosed conduction abnormality and was not included in the study. Most elephants had a sinus arrhythmia in at least one position. With increasing age, there was a trend toward a slower heart rate and significantly longer P waves. Increasing body weight was significantly correlated with longer QT intervals and T waves with lower amplitude. Compared with measurements in ST, LL resulted in P waves and QRS complexes with shorter amplitude, U waves with greater amplitude, PR intervals with shorter duration, and an increased heart rate. Compared with measurements in LL, RL resulted in larger QRS complexes. U waves were most commonly detected in RL and LL. Mean electrical axis calculated in the frontal plane were as follows: standing range −125 to +141°, mean −5°; left lateral range −15 to +104°, mean 27°; right lateral range −16 to +78°, mean 9°. Position-specific reference ranges should be used when interpreting ECGs, and clinicians must be aware of how age and body weight may affect the ECG.

Immune responses of Asian elephants (Elephas maximus) to commercial tetanus toxoid vaccine

Although captive elephants are commonly vaccinated annually against tetanus using commercially available tetanus toxoid vaccines marketed for use in horses and livestock, no data exists to prove that tetanus toxoid vaccination produces measurable antibody titers in elephants. An ELISA test was created to measure antibody responses to tetanus toxoid vaccinations in 22 Asian elephants ranging in age from 24 to 56 years (mean age 39 years) over a 7-month period. All animals had been previously vaccinated with tetanus toxoid vaccine, with the last booster administered 4 years before the start of the study. The great majority of elephants had titers prior to booster vaccination, and following revaccination all elephants demonstrated anamnestic increases in titers, indicating that this species does respond to tetanus vaccination. Surprisingly older animals mounted a significantly higher response to revaccination than did younger animals.

Urinalysis in Asian Elephants (Elephas maximus)

Abstract Urine was collected from 22 healthy female adult Asian elephants (Elephas maximus) and analyzed for the purpose of determining normal biochemical and microscopic parameters. Findings included urine that was less concentrated compared to other mammals, predominantly alkaline pH, crystalluria of varying types in all samples, and minimal cellularity. Glucose and urobilinogen were not detected in any samples. Trace ketones and trace bilirubin occurred in two different samples. Trace blood was identified in another sample. Three samples tested positive for protein via dipstick but were confirmed negative through the sulfosalicylic acid test. Two samples contained mucus threads. Bacteria were seen microscopically in four samples, and could be cultured from six others, but, because of the lack of an associated inflammatory response and the heterogeneous populations of organisms observed, were considered to be contaminants from the distal urethra, the vestibulovulva, or the environment. Because of the variability in elephant urine, baseline values for elephants within captive herds should be obtained and regular assessments should be performed over time to allow trending of data. Establishment of normal urine values provides an important tool in elephant health care.

Reference intervals for acute phase protein and serum protein electrophoresis values in captive Asian elephants (Elephas maximus)

Acute phase protein (APP) immunoassays and serum protein electrophoresis (SPEP) are assays for evaluating the inflammatory response and have use as diagnostic tools in a variety of species. Acute phase proteins are markers of inflammation that are highly conserved across different species while SPEP separates and quantifies serum protein fractions based on their physical properties. In the current study, serum samples from 35 clinically healthy Asian elephants (Elephas maximus) were analyzed using automated assays for C-reactive protein, serum amyloid A, and haptoglobin and SPEP. Robust methods were used to generate reference intervals for the APPs: C-reactive protein (1.3–12.8 mg/l), serum amyloid A (0–47.5 mg/l), and haptoglobin (0–1.10 mg/ml). In addition, SPEP was performed on these samples to establish reference intervals for each protein fraction. A combination of APPs and SPEP measurements are valuable adjunctive diagnostic tools in elephant health care.

Baseline levels of trace metals in blood of captive Asian elephants (Elephas maximus).

Abstract:  Whole blood from 33 healthy captive Asian elephants (Elephas maximus) was analyzed for 12 trace elements: aluminum, chromium, manganese, cobalt, nickel, copper, zinc, arsenic, selenium, cadmium, mercury, and lead for the purpose of estimating preliminary baseline population parameters for these minerals. Metals were quantified by inductively coupled plasma mass spectroscopy. Baseline ranges for all animals and for all trace elements were comparable to normal concentrations reported in other species. This is the first report of normal trace element levels in the blood of captive elephants.

Nonsurgical repair of an umbilical hernia in two Asian elephant calves (Elephas maximus).

Abstract Umbilical hernias were diagnosed in two captive-born, female Asian elephant (Elephas maximus) calves several weeks after birth. Daily manual reduction of the hernias for 5 wk in the first case and for 5 mo in the second resulted in complete closure of the defects. Nonsurgical repair of uncomplicated, fully reducible umbilical hernias in Asian elephants can be an alternative to surgery.

MEDICAL MANAGEMENT OF A CORNEAL STROMAL ABSCESS IN A FEMALE ASIAN ELEPHANT (ELEPHAS MAXIMUS)

Abstract A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk.

Severe laminitis in multiple zoo species

A 10-year record review from a zoological institution in the western USA identified four cases of severe laminitis resulting in rotation and protrusion of the third phalanx through the sole. Laminitis is reported in a Masai giraffe (Giraffa camelopardalis tippelskirchi), a Sichuan takin (Budorcas taxicolor tibetana), a greater Malayan chevrotain (Tragulus napu) and a giant eland (Taurotragus derbianus). This is the first report of severe laminitis with pedal bone rotation and protrusion in multiple species of non-domestic hoofstock, and the first report of this disease in three of these species (takin, chevrotain, and giant eland).