Bronchial Tree System Analysis of Live Beluga Whale (Delphinapterus leucas) Using Bronchoscopy.

Cetaceans, including beluga whales (Delphinapterus leucas), have high morbidity and mortality rates due to bacterial or fungal lower respiratory infections. Bronchoalveolar lavage fluid (BALF) collection by bronchoscopy is beneficial for detecting pathogenic microorganisms in the lower respiratory tract. Efficient and safe bronchoscopy requires characterizing the bronchial tree systems of beluga whales, as no reports exist on bronchial length and bifurcation. In this study, bronchoscopy was performed on five captive beluga whales (9-44 years old) to detect bronchial length and bifurcation. The lengths from the blowhole to the scope impassable points due to the minimized bronchi diameters of the left principal bronchus (LPB), right principal bronchus (RPB), and tracheal bronchus (TB) were 110-155, 110-150, and 80-110 cm, respectively, and were correlated with the body length. Bronchoscopy identified more than 10, 10, and 6 bifurcated bronchi from the LPB, RPB, and TB, respectively. This is the first report to clarify the differences in bronchial tree systems between beluga whales and other cetaceans, as well as the differences for each individual beluga whale. These results could be useful for obtaining BALF via bronchoscopy to detect pathogenic microorganisms causing infections in the lower respiratory tract of beluga whales.

Midazolam and butorphanol combination for sedating beluga whales (Delphinapterus leucas).

Safe sedation doses for performing minor procedures such as bronchoscopy, endoscopy, and tooth extraction for beluga whales (Delphinapterus leucas) require elucidation. This study aimed to provide suggestions for determining appropriate midazolam and butorphanol doses to adequately sedate beluga whales to complete procedures and minimize the risk of side effects. We administered midazolam and butorphanol to six captive beluga whales (9-44 years old). Topical lidocaine anesthesia was administered during bronchoscopy. The sedation doses for the beluga whales varied from 0.020 to 0.122 mg/kg for midazolam and from 0.020 to 0.061 mg/kg for butorphanol. In beluga whales, optimal midazolam and butorphanol doses were lowest in old whales. These findings contribute to knowledge regarding appropriate sedation and prevention of overdose accidents during minor procedures in beluga whales.

Placental and breastmilk transfer of voriconazole to offspring from pregnant and lactating bottlenose dolphins (Tursiops truncatus).

Fungal pneumonia is a common disease in bottlenose dolphins (Tursiops truncatus), including pregnant and lactating ones. Voriconazole (VRCZ) is commonly used to treat respiratory fungal infections in this species; however, it is unknown whether VRCZ is transferred via the placenta and breastmilk and whether its usage is safe in pregnant and lactating dolphins. We measured VRCZ concentrations in breastmilk and dams', umbilical cord, and calves' plasma samples from four dam-calf dolphin pairs in the Port of Nagoya Public Aquarium, Japan, treated with or without VRCZ. Three pregnant and/or lactating dams were administered VRCZ (loading dose 1.5-2.3 mg/kg, for 3 days; maintenance dose 1.5-3.1 mg/kg, every 5-18 days), twice daily, orally, without side effects in dams or calves. VRCZ was detected in two dams' umbilical cord plasma (0.14 and 2.35 µg/ml) and in one calf's plasma (0.18 µg/ml), collected immediately after birth. Further, VRCZ was detected in breastmilk samples (maximum 13.45 µg/ml) from three VRCZ-administered dams and in plasma from three calves (maximum 7.54 µg/ml) given or nursed from VRCZ-administered dams' breastmilk. The calves' plasma VRCZ concentrations varied, depending on the amount of breastmilk and food consumed. VRCZ concentrations were higher in breastmilk samples than in dams' plasma. To our knowledge, this is the first report on placental and breastmilk VRCZ transfer to offspring in bottlenose dolphins. During VRCZ medication in pregnant and lactating bottlenose dolphins, it is crucial to monitor plasma VRCZ concentrations and any side effects in dams as well as in their calves.

First isolation of voriconazole-resistant Candida albicans, C. tropicalis, and Aspergillus niger from the blowholes of bottlenose dolphins (Tursiops truncatus).

Pulmonary mycosis is a fungal disease that commonly affects bottlenose dolphins (Tursiops truncatus) and is generally treated by the oral administration of azoles, such as itraconazole (ITZ) and voriconazole (VRZ). However, antifungal susceptibility testing of clinical isolates has not been well performed as a routine clinical examination in aquaria. In this study, we collected fungal species from the blowholes of 14 bottlenose dolphins, of which 12 were treated with ITZ or VRZ. All dolphins were housed in the Port of Nagoya Public Aquarium. The fungal species Candida albicans, C. tropicalis, C. glabrata, Aspergillus fumigatus, and A. niger were isolated. E-tests were performed to determine the minimum inhibitory concentrations (MICs) of ITZ and VRZ on these isolates. VRZ-resistant C. tropicalis (MIC: >32 µg/ml) and A. niger (MIC: >32 µg/ml) were isolated from three dolphins treated with ITZ or VRZ. Additionally, azole-resistant isolates of C. albicans and C. glabrata were collected from two dolphins that had never received azole therapy. To the best of our knowledge, our study is the first to report the isolation of VRZ-resistant C. albicans, C. tropicalis, and A. niger from the blowholes of bottlenose dolphins. Thus, antifungal susceptibility testing is a crucial strategy for selecting antifungal agents to treat respiratory fungal infections in bottlenose dolphins in aquaria.

Leukopenia induced by micafungin in a bottlenose dolphin (Tursiops truncatus): a case report.

A bottlenose dolphin (Tursiops truncatus) housed in the Port of Nagoya Public Aquarium (PNPA) presented with symptomatic pneumonia caused by Aspergillus fumigatus. The dolphin was treated with micafungin. On days 2 and 11 after the first administration of micafungin, results from a physical examination and laboratory test indicated a decline of body temperature (BT) and leukopenia, with lowest BT, white blood cells (WBCs), and segmented neutrophils (SEGs) of 34.2°C, 600 cells/µl, and 67 cells/µl, respectively. BT, WBCs, and SEGs returned to normal range after administration of granulocyte colony stimulating factor (G-CSF). To the best of our knowledge, this is the first report of micafungin-induced decline of BT and leukopenia that was successfully treated with G-CSF in a bottlenose dolphin.

Plasma metabolomic analysis in mature female common bottlenose dolphins: profiling the characteristics of metabolites after overnight fasting by comparison with data in beagle dogs.

The present study was aimed at determining the characteristics of plasma metabolites in bottlenose dolphins to provide a greater understanding of their metabolism and to obtain information for the health management of cetaceans. Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) and liquid chromatograph-time-of-flight mass spectrometry (LC-TOFMS) were conducted on plasma samples after overnight fasting from three common bottlenose dolphins as well as three beagle dogs (representative terrestrial carnivores) for comparison. In total, 257 and 227 plasma metabolites were identified in the dolphins and the dogs, respectively. Although a small number of animals were used for each species, the heatmap patterns, a principal component analysis and a cluster analysis confirmed that the composition of metabolites could be segregated from each other. Of 257 compounds detected in dolphin plasma, 24 compounds including branched amino acids, creatinine, urea, and methylhistidine were more abundant than in dogs; 26 compounds including long-chained acyl-carnitines and fatty acids, astaxanthin, and pantothenic acid were detected only in dolphins. In contrast, 25 compounds containing lactic acid and glycerol 3-phosphate were lower in dolphins compared to dogs. These data imply active protein metabolism, differences in usage of lipids, a unique urea cycle, and a low activity of the glycolytic pathway in dolphins.

Environmental isolates of fungi from aquarium pools housing killer whales (Orcinus orca).

Systemic mycoses in killer whales (Orcinus orca) are rare diseases, but have been reported. Two killer whales died by fungal infections at the Port of Nagoya Public Aquarium in Japan. In this study, the fungal flora of the pool environment at the aquarium was characterized. Alternaria spp., Aspergillus spp. (A. fumigatus, A. niger, A. versicolor), Fusarium spp. and Penicillium spp. were isolated from the air and the pool surroundings. The other isolates were identified as fungal species non-pathogenic for mammals. However, the species of fungi isolated from the environmental samples in this study were not the same as those isolated from the cases of disease in killer whales previously reported.

Cyclical changes of plasma sex steroids in captive breeding loggerhead turtles (Caretta caretta).

Loggerhead turtles (Caretta caretta) have been laying eggs in an indoor artificial beach since 1995, at the Port of Nagoya Public Aquarium (PNPA). Four individuals landed and laid eggs several times during the breeding period in 1996. Blood samples from these individuals were collected monthly throughout that year in order to investigate the changes in sex steroid hormones (testosterone, estradiol, and progesterone). In addition, detailed investigations were conducted daily during the breeding period on one particular individual that landed and laid eggs five times in 1998. Each steroid hormone changed periodically based on the laying cycle, and extraordinarily high levels of estradiol were noted even during the breeding period. In reports regarding the green turtle (Chelonia mydas), extremely different results were observed. Some of the obtained data suggest that progesterone induced ovulation. Data from a completely artificial environment such as the one at the PNPA provides elucidation of the reproductive physiology in these endangered species.