DEVELOPMENT OF A MOBILITY ASSESSMENT SCORE FOR EVALUATION OF THE EFFECTS OF ORAL HYALURONIC ACID ON CLINICAL LAMENESS IN ASIAN SMALL-CLAWED OTTERS (AONYX CINEREA) AND AFRICAN SPOT-NECKED OTTERS (HYDRICTIS MACULICOLIS) UNDER HUMAN CARE.

Oral hyaluronic acid has been shown to reduce inflammation and pain in humans with osteoarthritis. Eight Asian small-clawed otters (Aonyx cinerea) and two African spot-necked otters (Hydrictis maculicolis) with varying degrees of osteoarthritic changes identified on radiographs were selected for a randomized, double-blinded, placebo-controlled clinical trial. Animal husbandry staff completed otter mobility assessment (OMA) questionnaires for each animal prior to study commencement and following either oral hyaluronic acid at a loading dose of 4 mg/kg PO SID for 10 d followed by a maintenance dose of 2 mg/kg PO SID for 20 d, or placebo for 30 d. Four veterinarians with experience assessing otters watched randomized videos of otter gaits and assigned a clinical lameness score. Two additional evaluators watched the videos: an experienced veterinarian in small animal practice and a final-year veterinary student. All evaluators for OMA and clinical lameness score were blinded to treatment group. Radiographs performed prior to, and following, the study were assessed by a board-certified radiologist (Dennison). The OMA questionnaire had high reliability coefficients and correlated strongly with clinical gait scores and radiographic assessment. Although hyaluronic acid appears to be safe for use in otters at the dose described, there was no observed significant effect of hyaluronic acid on clinical lameness scores, OMA scores, or radiographic assessment of the limbs. The development of the OMA questionnaire is a promising tool for evaluating lameness in managed-care otters and may be further validated in future studies investigating therapeutics or incorporated as a component of animal welfare assessment.

Chronic nonchylous lymphatic pleural effusion in a bottlenose dolphin (Tursiops truncatus).

CASE DESCRIPTION: A 19-year-old male bottlenose dolphin (Tursiops truncatus) presented with inappetence and avoidant behavior. CLINICAL FINDINGS: Ultrasound revealed a large-volume left-sided pleural effusion, which was consistent with chronic nonchylous lymphatic effusion and mild chronic hemorrhage by cytology. Computed tomography identified ipsilateral rib fractures, atelectasis, nodular pleuritis, marginal lymph node enlargement, and suspected dilation of the thoracic duct and internal thoracic veins. Fifteen lipids were significantly higher in serum of the dolphin as compared with controls (n = 3) using nontargeted lipidomics. TREATMENT AND OUTCOME: A series of thoracentesis procedures were performed. Follow-up CT demonstrated marked reduction in pleural effusion with persistence of thoracic duct dilation and mass-like areas of pleural thickening. Ultrasonographic resolution of pleural effusion occurred 14 months after presentation; however, recrudescence was noted 5 months later. Over a total of 24 months, 21.52 L of pleural effusion was removed. Despite the presence of pleural effusion, the patient was clinically stable during this time and quality of life was considered good on the basis of continuous animal welfare evaluations. Humane euthanasia was elected following acute clinical decline 27 months after initial diagnosis. Necropsy confirmed severe pleural effusion, chronic severe pleural fibrosis with chronic hemorrhage, and mediastinal fibrosis with entrapped lymph nodes and thymic tissue. CLINICAL RELEVANCE: Pleuritis and effusion were suspected sequelae of previous rib fractures. To our knowledge, this is the first report of nonchylous lymphatic pleural effusion with repeated pleural drainage and diagnostic imaging for clinical management in a bottlenose dolphin.

EFFICACY OF HUMAN RECOMBINANT GRANULOCYTE COLONY-STIMULATING FACTOR (G-CSF, FILGRASTIM; NEUPOGEN®) IN NEUTROPENIC CETACEANS.

Neutrophils are one of the initial cell lines of protection against pathogens, and when their concentrations in the blood are low, animals are highly susceptible to infections. Neutropenia has been reported in cetaceans secondary to administration of systemic sulfa antibiotics or antifungal medications and severe, overwhelming infection. Filgrastim was administered to treat neutropenia over a 15-y period in 11 cetaceans comprising four species-beluga (Delphinapterus leucas, n = 1), bottlenose dolphin (Tursiops truncatus, n = 4), killer whale (Orcinus orca, n = 5), and short-finned pilot whale (Globicephala macrorhynchus, n = 1)] ranging in age from 1 wk to >24 y. Seven study animals received multiple doses (2-6). All animals responded to at least one dose (1-7 µg/kg) of parenteral filgrastim characterized by an increase in peripheral immature (band) neutrophils, segmented neutrophils, or both. In most cases (9/11), neutrophil counts increased within 48 h of a single dose. Duration of response varied but was at least 2 wk in eight of the 11 animals and 5-9 d in the remaining animals. No adverse reactions were observed in any cases.

CEREBROSPINAL FLUID SAMPLING IN A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) UNDER GENERAL ANESTHESIA.

Brucella ceti, associated with neurobrucellosis, has been isolated from cerebrospinal fluid (CSF) of postmortem cetaceans. A 106-kg, stranded female bottlenose dolphin (Tursiops truncatus) presented with serum antibodies to Brucella spp. via competitive enzyme-linked immunosorbent assay and fluorescence polarization assay. Polymerase chain reaction (PCR) and culture of whole blood, bronchoalveolar fluid, and rectal, nasal, and genital swabs for Brucella spp. were consistently negative. Serial computed tomography revealed mild focal dilatation of brain ventricles. CSF sampling was warranted to exclude neurobrucellosis. Sedation was achieved with 30 mg diazepam (0.28 mg/kg) orally 2.5 hours prior to arrival in hospital, followed by 5.3 mg midazolam (0.05 mg/kg) intramuscularly, and anesthetic induction with 2.5 mg midazolam (0.02 mg/kg) and 200 mg propofol (2 mg/kg) administered slowly intravenously, followed by intubation and maintenance on sevoflurane using controlled mechanical and apneustic anesthesia ventilation. The atlanto-occipital joint was opened by flexing the upper cervical region with the animal in left lateral recumbency. A 20-ga × 6-inch spinal needle was advanced into the cisterna magna using radiographic guidance. CSF was collected successfully with no neurological deficits appreciable on recovery. Brucella spp. was not identified via PCR or culture. This represents the first report of an antemortem CSF tap in a cetacean.

Testosterone and progesterone concentrations in blow samples are biologically relevant in belugas (Delphinapterus leucas).

Steroid hormone analysis in blow (respiratory vapor) may provide a minimally invasive way to assess the reproductive status of wild cetaceans. Biological validation of the method is needed to allow for the interpretation of hormone measurements in blow samples. Utilizing samples collected from trained belugas (Delphinapterus leucas, n=20), enzyme immunoassays for testosterone and progesterone were validated for use with beluga blow samples. Testosterone concentrations in 40 matched blood and blow samples collected from 4 male belugas demonstrated a positive correlation (R2=0.52, p<0.0001). Progesterone concentrations in 64 matching blood and blow samples from 11 females were also positively correlated (R2=0.60, p<0.0001). Testosterone concentrations (mean±SD) in blow samples collected from adult males (119.3±14.2pg/ml) were higher (p<0.01) than that of a juvenile male (<8years) (59.4±6.5pg/ml) or female belugas (54.1±25.7pg/ml). Among adult males, testosterone concentrations in blow demonstrated a seasonal pattern of secretion, with peak secretion occurring during the breeding season (February-April, 136.95±33.8pg/ml). Progesterone concentrations in blow varied by reproductive status; pregnant females (410.6±87.8pg/ml) and females in the luteal phase of the estrous cycle (339.5±51.0pg/ml) had higher (p<0.0001) blow progesterone concentrations than non-pregnant females without a corpus luteum (242.5±27.3pg/ml). Results indicate that blow sample analysis can be used to detect variation in reproductive states associated with large differences in circulating testosterone or progesterone in belugas.

The first year of behavioral development and maternal care of beluga (Delphinapterus leucas) calves in human care.

The current study provides additional information for the behavioral development and maternal care of belugas or white whales (Delphinapterus leucas) in the care of humans. The behaviors and mother-calf interactions of two female beluga calves were recorded from birth to 12 months as part of a longitudinal study of beluga behavioral development. As expected, the primary calf activity for both calves involved swimming with their mothers. The calves initiated the majority of the separations from and reunions with their mothers and exhibited early bouts of independence. Both mothers bonded with their calves and displayed similar maternal care behaviors but exhibited different behavioral patterns. Despite differences in social groupings, housing, and physical health, the two female belugas followed the behavioral development of beluga calves observed previously.

Management of twin pregnancy and perinatal concerns in a Beluga (Delphinapterus leucas).

A 22-yr-old multiparous beluga, Delphinapterus leucas, with consistently elevated serum progesterone concentrations post-artificial insemination was diagnosed with viable twins at 149 days postconception. Twins were of similar size at least until day 264, the last point when ultrasound measurements of both twins were made. However, ultrasound was used to determine the viability of both fetuses on days 365, 393, and 400. After 90% of normal gestation, or 434 days, steroids were administered to encourage fetal lung maturation. Seven days later a 40.9-kg live female calf was delivered headfirst. A second 22.7-kg stillborn calf was delivered in fluke-first presentation 8 hr later. Immediately after birth, the live calf was administered surfactant intratracheally. The next day, it was given beluga immunoglobulin intramuscularly, and started on oral antibiotics and provided nutritional support via an oral gastric tube. The calf started nursing voluntarily on day 3. Antibiotic and nutritional support was discontinued on day 10. Bimonthly weight and length measurements demonstrated that after an initial increased growth rate, the calf has grown within normal parameters after birth. This calf represents the first known successful surviving twin of any cetacean species and sets an important precedent for treatment modalities that may be available to assist the premature cetacean neonate.

Mercury speciation and biomagnification in the food web of Caddo Lake, Texas and Louisiana, USA, a subtropical freshwater ecosystem.

We studied the biomagnification of total mercury and methylmercury in a subtropical freshwater lake, Caddo Lake, Texas and Louisiana, USA. The present study is unique in that it not only included invertebrates (seven species) and fish (six species) but also an amphibian (one species), reptiles (three species), and mammals (three species). Nonfish vertebrates such as those included in the present study are often not included in assessments of trophic transfer of Hg. Mean trophic position (determined using stable isotopes of nitrogen) ranged from 2.0 (indicative of a primary consumer) to 3.8 (indicative of a tertiary consumer). Mean total Hg concentrations ranged from 36 to 3,292 ng/g dry weight in muscle and whole body and from 150 to 30,171 ng/g dry weight in liver. Most of the Hg in muscle and whole-body tissue was found as methylmercury, and at least 50% of the Hg found in liver was in the inorganic form (with the exception of largemouth bass, Micropterus salmoides). Mercury concentrations were positively correlated with trophic position, indicating that biomagnification occurs in the food web of Caddo Lake. The food web magnification factors (FWMFs; slope of the relationship between mean Hg concentration and trophic position) for both total Hg and methylmercury were similar to those observed in other studies. Because most of the total Hg in consumers was methylmercury, the FWMF for methylmercury was not significantly different from the FWMF for total Hg. Some vertebrates examined in the present study had low Hg concentrations in their tissues similar to those observed in invertebrates, whereas others had concentrations of Hg in their tissues that in previous studies have been associated with negative health consequences in fish.

Characterization of progressive keratitis in otariids.

OBJECTIVE: To characterize a form of progressive keratitis that occurs commonly in otariids. MATERIALS AND METHODS: One hundred and thirteen captive otariids were evaluated by ophthalmologic examination and digital photography. RESULTS: Forty-six females and 67 males were in the reference population, average age of 14 years. California sea lions predominated (n = 100); there were also six Steller sea lions, five brown fur seals, one Guadalupe fur seal and one northern fur seal. Three stages of progressive keratitis are described. Overall, 64.6% animals and 142 eyes from 113 animals (62.8%) were affected with one of three stages. The mildest form, Stage 1 keratitis, occurred in 78 of 226 eyes (34.5%); the intermediate Stage 2 keratitis occurred in 30 of 226 eyes (13.3%); and the most severe, Stage 3 keratitis, occurred in 34 of 226 eyes (15%). All but six animals had bilateral disease. Animals with Stage 1 keratitis were significantly younger than those in more advanced stages. DISCUSSION: 'Otariid Keratitis' occurs in all populations of eared seals evaluated. A large-scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs. Age may be important since exposure accumulates with aging. Progression of the disease is also associated with secondary opportunistic bacterial and fungal infections. The surface immune system may be imbalanced contributing to these infections and progression.

Risk factors associated with cataracts and lens luxations in captive pinnipeds in the United States and the Bahamas.

OBJECTIVE: To determine risk factors for lens luxation and cataracts in captive pinnipeds in the United States and the Bahamas. DESIGN: Cross-sectional study. ANIMALS: 111 pinnipeds (99 California sea lions [Zalophus californianus], 10 harbor seals [Phoca vitulina], and 2 walruses [Odobenus rosmarus]) from 9 facilities. PROCEDURES: Eyes of each pinniped were examined by a veterinary ophthalmologist for the presence of cataracts or lens luxations and photographed. Information detailing husbandry practices, history, and facilities was collected with a questionnaire, and descriptive statistical analyses were performed for continuous and categorical variables. Odds ratios and associated 95% confidence intervals were estimated from the final model. RESULTS: Risk factors for lens luxation, cataracts, or both included age >or= 15 years, history of fighting, history of ocular disease, and insufficient access to shade. CONCLUSIONS AND CLINICAL RELEVANCE: Diseases of the lens commonly affect captive pinnipeds. Access to UV-protective shade, early identification and medical management of ocular diseases, and prevention of fighting can limit the frequency or severity of lens-related disease in this population. An extended life span may result from captivity, but this also allows development of pathological changes associated with aging, including cataracts.