Antebrachial fractures in four captive polar bears (Ursus maritimus)

OBJECTIVE: To identify common risk factors for antebrachial fractures of captive polar bears and to evaluate outcome after fracture repair. STUDY DESIGN: Retrospective study. ANIMALS: Four captive polar bears. METHODS: United States zoological collections were surveyed to determine the prevalence of fractures in captive polar bears. Medical records of captive polar bears that had antebrachial fractures were reviewed for signalment, history, physical and radiographic findings, fracture management, postoperative care, and outcome. Serum samples from healthy bears and bears with antebrachial fractures were assayed for 25-hydroxyvitamin D (25-OHD) concentrations. RESULTS: Nineteen fractures (12 polar bears) occurred from 1974 to 2002; 12 fractures involved the antebrachium. Management of 4 antebrachial fractures was reviewed; 3 were repaired by internal fixation and 1 by external coaptation. Fractures healed and bears were returned to exhibit on average 3 months postfracture. Of 11 serum samples assayed for 25-OHD concentrations, 6 were below normal, 1 was low normal and 4 were within normal reference intervals. The 7 bears with subnormal or low normal values were housed in 2 zoos. Subnormal vitamin D concentrations were identified in 2 of 3 bears with fractures. CONCLUSIONS: Fracture disease is not uncommon in captive polar bears. Additional research is necessary to explore the role of nutrition in polar bear fracture disease. CLINICAL RELEVANCE: Internal fixation of antebrachial fractures is feasible and reasonably well tolerated in captive polar bears.     

Molecular detection of filarial nematode parasites in Japanese black bears (Ursus thibetanus japonicus) from Iwate Prefecture, Japan

This study aimed to detect filarial parasites in blood samples of Japanese black bears (Ursus thibetanus japonicus) collected from Iwate Prefecture, Japan. Positive amplicons were obtained from 26 out of 30 samples by nested PCR targeting 18S ribosomal RNA gene and first internal transcribed spacer regions. DNA sequences of Mansonella sp. close to M. ozzardi and Dirofilaria sp. were detected for eight and 11 positive amplicons, respectively. Co-infection was detected for the remaining seven amplicons. Dirofilaria sp. was identified as D. ursi by further genetic analysis of 5S ribosomal RNA gene sequence. The results of this study will contribute to further investigations of Japanese black bears for monitoring their risk as a reservoir of possible zoonotic filarial parasites.     

Detection and prevalence of four different hemotropic Mycoplasma spp. in Eastern North Carolina American black bears (Ursus americanus)

Hemotropic Mycoplasma spp. are globally emerging, obligate parasitic, epierythrocytic bacteria that infect many vertebrates, including humans. Hemoplasma infection can cause acute life-threatening symptoms or lead to a chronic sub-clinical carrier state. Hemotropic Mycoplasma spp. transmission, prevalence, and host specificity are uncertain. The purpose of this study was to determine the molecular prevalence of Mycoplasma species in blood from 68 free-ranging black bears from the eastern coast of North Carolina. DNA amplification of Mycoplasma 16S rRNA gene identified four distinct species infecting 34/68 (50%) of the black bear blood samples, including Candidatus M. haematoparvum. The high prevalence of hemotropic Mycoplasma infection in this wildlife species highlights the importance of understanding intra and inter species transmission. Black bears may play a role in the transmission of hemotropic Mycoplasma spp. between animals, arthropod vectors, and humans. Further studies are needed to elucidate black bears as a potential reservoir for hemotropic Mycoplasma infections.     

亚洲黑熊电刺激采精及精液品质分析

采用电刺激法对 18头亚洲黑熊进行了 2 3次精液采集 ,并对所得精液进行了品质分析。亚洲黑熊每次射精量平均体积 (0 .2 5 9± 0 .185 )mL ,pH值 7.0± 0 .0 ,密度 (13.90± 8.19)× 10 8/mL ,活力 (75 .83± 14 .2 9) % ,运动状态 3.75±0 .2 7,畸形率 (2 3.0 9± 9.5 4 ) % ,顶体完整率 (80 .17± 13.2 6 ) %。盐酸氯氨酮与麻保静混合麻醉是一种适合黑熊电刺激采精的麻醉方法。     

Effect of the change of social environment on the behavior of a captive brown bear (Ursus arctos)

We observed the behavior of a captive sterilized male brown bear before and after the death of his female sibling to investigate the effect of the change of social environment on his behavior and welfare. Observations were carried out by continuous recording during daylight for 6 wk prior to hibernation when the bear was kept with the sibling, and they were repeated 2 years later when the bear was alone (total observation time is 108 h). Feeding, moving, and the total amount of time spent resting (including sleeping and alert inactive) were not affected by the change of social environment. However, when the bear was alone, the percentage of time he spent alert inactive almost trebled (pair, 17.7 ± 3.3%; alone, 48.5 ± 5.5%; P < 0.001), and the time spent sleeping was less than one-third (pair, 51.1 ± 6.1%; alone, 14.2 ± 5.0%; P < 0.001) than when the female was present. The bear spent most of his sleeping time in lateral lying posture (a posture probably associated with rapid eyes movement sleep). The percentage of time dedicated to this posture was significantly reduced after the death of his sibling (pair, 35.9 ± 7.4%; alone, 15.0 ± 5.4%; P < 0.05), whereas the percentage of time spent in quadrupedal posture increased (pair, 17.1 ± 5.4%; alone, 37.8 ± 7.8; P < 0.05). One of the possible reasons for these changes may be an increased risk perception of the bear after the death of his sibling. Our results highlight the importance of social environment and of its changes, which should be carefully considered to maintain captive bears in good welfare conditions.     

Comparative anatomy of the radial sesamoid bone in the polar bear (Ursus maritimus), the brown bear (Ursus arctos) and the giant panda (Ailuropoda melanoleuca).

Since we have clarified the manipulation mechanism using the radial sesamoid (RS) in the giant panda (Ailuropoda melanoleuca), our aim in this study is to examine the position, shape and function of the RS morphologically, and to observe the attachment to the RS of the M. abductor pollicis longus and the M. opponens pollicis in the other Ursidae species. So, we focused on the carpus and manus of the polar bear (Ursus maritimus) and the brown bear (Ursus arctos) in this study. The RS was tightly articulated to the radial carpal, and could not adduct-abduct independently of the radial carpal. The M. abductor pollicis longus tendon and the M. opponens pollicis belly were attached to the RS, independently. In the polar bear, the deep concave and the flat surface were confirmed in attachment area for these two muscles. The morphological relationship between the RS and the M. abductor pollicis longus and the M. opponens pollicis in the two species of bears were essentially consistent with that in the giant panda. It also demonstrated that the manipulation mechanism of the giant panda has been completely based on the functional relationship between the small RS, and the M. abductor pollicis longus and the M. opponens pollicis in Ursidae species.     

Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation

Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and without eating, drinking, urinating or defecating. We describe experimental studies on free-ranging bears that document their abilities to completely resolve cutaneous cuts and punctures incurred during or prior to hibernation. We induced small, full-thickness cutaneous wounds (biopsies or incisions) during early denning, and re-biopsied sites 2-3 months later (near the end of denning). Routine histological methods were used to characterize these skin samples. All biopsied sites with respect to secondary intention (open circular biopsies) and primary intention (sutured sites) healed, with evidence of initial eschar (scab) formation, completeness of healed epidermis and dermal layers, dyskeratosis (inclusion cysts), and abilities to produce hair follicles. These healing abilities of hibernating black bears are a clear survival advantage to animals injured before or during denning. Bears are known to have elevated levels of hibernation induction trigger (delta-opioid receptor agonist) and ursodeoxycholic acid (major bile acid within plasma, mostly conjugated with taurine) during hibernation, which may relate to these wound-healing abilities. Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine. Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries.     

周岁黑熊脾脏的组织学和组织化学研究

采用石蜡和冰冻切片方法，进行３Ｍ·Ｅ和Ｗｉｌｄｅｒ染色，并以酸性α－醋酸萘醋酶（ＡＮＡＥ）法显示Ｔ淋巴细胞的分布。结果表明：周岁黑熊（Ｓｅｌｅｎａｒｃｔｏｓｔｈｉｂｅｔａｎｕｓ）脾脏小梁较多，脾窦发育不良．动脉周围淋巴鞘发达；鞘动脉位于脾索内，靠近边缘区；椭球厚为３０－４０μｍ。ＡＮＡＥ阳性反应的淋巴细胞主要分布于白髓的中央动脉周围淋巴鞘内，其次是脾小结外周，边缘区和椭球内。     

Morphological and molecular phylogenetical identification of Tricodectes pinguis from Japanese black bears (Ursus thibetanus japonicus) in Aomori Prefecture,Japan

Trichodectes pinguis, referred to commonly as the bear-biting louse, has been reported in several bear species. However, graphical (blurred or coarse) and genetic information on the louse is limited. In this study, we identified T. pinguis collected from Japanese black bears in the Aomori Prefecture, Japan. We confirmed 12S rDNA sequences derived from the collected T. pinguis and performed molecular phylogenetic analysis based on 12S rDNA. The analysis revealed the parasitic louse to be T. pinguis. Interestingly, the body size of T. pinguis found in this study was smaller than the previous recorded body size of them in Japan and Turkey. To better understand the biting louse infesting bears, morphometric and genetic information from other bear hosts needs to be accumulated.     

The Incidence of Lymphoplasmacytic Gastritis in the Fundus and Antrum of Cynomolgus Monkey ( Macaca fascicularis ) Stomachs

Lymphoplasmacytic gastritis is a concern for toxicological pathologists reading preclinical, non-human primate toxicity studies because subtle gastric changes which could be treatment-related may be masked and gastritis lesions may be confused with treatment-related effects and thus a gastric finding may be incorrectly assigned as a treatment-related lesion. This paper discusses the incidence of lymphoplasmacytic gastritis in cynomolgus monkeys at a contract research organization. The incidence of lymphoplasmacytic gastritis in the fundus and antrum of control cynomolgus monkeys on 18 non-gastric compound studies, was scored. The average fundus score ranged from 0.3 to 1.5 and the average antral score ranged from 0.9 to 3.5 in the cynomolgus monkey stomachs examined. The number of affected control animals in a study ranged from 0 to 5 control animals. No correlation between the route of vehicle administration and the severity or incidence of the lesions was noted. The percentage incidence of affected animals ranged from 0 to 100%. An increased incidence lymphoplasmatic gastritis from 2000 to 2004 was noted. The implications of lymphoplasmacytic gastritis in cynomolgus monkeys used for acute toxicity studies are discussed.     

Clistobothrium sp. (Cestoda: Tetraphyllidea) in oarfish (Regalecus russelii) stranded on the coast of Akita Prefecture, Japan

Oarfish (Regalecus russelii Cuvier) are mesopelagic fish with little known about their life history. Oarfish live in deep water, making it difficult for researchers to collect specimens; thus, records of their parasitic helminths are limited. Two plerocercoids were found for the first time in an oarfish stranded on the coast of Akita Prefecture, Japan. These plerocercoids were identified as Clistobothrium sp. RR-1 using morphological and molecular analyses. It was revealed that oarfish represent one of the intermediate hosts of the genus Clistobothrium, and large sharks are the definitive hosts for these parasites.     

Post-Death Cloning of Endangered Jeju Black Cattle (Korean Native Cattle): Fertility and Serum Chemistry in a Cloned Bull and Cow and Their Offspring

To preserve Jeju black cattle (JBC; endangered native Korean cattle), a pair of cattle, namely a post-death cloned JBC bull and cow, were produced by somatic cell nuclear transfer (SCNT) in a previous study. In the present study, we examined the in vitro fertilization and reproductive potentials of these post-death cloned animals. Sperm motility, in vitro fertilization and developmental capacity were examined in a post-death cloned bull (Heuk Oll Dolee) and an extinct nuclear donor bull (BK94-13). We assessed reproductive ability in another post-death cloned cow (Heuk Woo Sunee) using cloned sperm for artificial insemination (AI). There were no differences in sperm motility or developmental potential of in vitro fertilized embryos between the post-death cloned bull and its extinct nuclear donor bull; however, the embryo development ratio was slightly higher in the cloned sperm group than in the nuclear donor sperm group. After one attempt at AI, the post-death cloned JBC cow became pregnant, and gestation proceeded normally until day 287. From this post-death cloned sire and dam, a JBC male calf (Heuk Woo Dolee) was delivered naturally (weight, 25 kg). The genetic paternity/maternity of the cloned JBC bull and cow with regard to their offspring was confirmed using International Society for Animal Genetics standard microsatellite markers. Presently, Heuk Woo Dolee is 5 months of age and growing normally. In addition, there were no significant differences in blood chemistry among the post-death cloned JBC bull, the cow, their offspring and cattle bred by AI. This is the first report showing that a pair of cattle, namely, a post-death cloned JBC bull and cow, had normal fertility. Therefore, SCNT can be used effectively to increase the population of endangered JBC.     

Low Incidence of an Altered Endometrial Epidermal Growth Factor (EGF) Profile in Repeat Breeder Holstein Heifers and Differential Effect of Parity on the EGF Profile Between Fertile Holstein (Dairy) and Japanese Black (Beef) Cattle

A high incidence (about 70%) of alteration in endometrial epidermal growth factor (EGF) profile, i.e., loss of 2 peaks on days 2–4 and 13–14, has been linked to a reduced fertility in multiparous repeat breeder Holstein cows. However, the EGF profile in Holstein heifers and other breeds (types) of cattle has not been investigated. In study 1, EGF concentrations were determined using endometrial tissues obtained by biopsy on days 3, 7 and 14 from 84 fertile Holstein heifers to obtain a normal range and 53 repeat breeder Holstein heifers to estimate incidence of alterations in the EGF profile. In repeat breeder heifers, EGF concentrations were similar to fertile controls on 3 days and five animals (9.4%) had an altered EGF profile with EGF concentrations below the normal range on days 3 and 14. In study 2, EGF concentrations on day 3 were repeatedly examined from the nulliparous period to the third postpartum period in 28 Holstein (dairy) and 47 Japanese Black (beef) cattle. The effect of parity on EGF concentrations on day 3 was different between Holstein and Japanese Black cattle. In Japanese Black cows, the EGF concentrations were consistently high throughout the study period, while in Holstein cows, the EGF concentrations decreased after the second calving. In conclusion, unlike multiparous repeat breeder Holstein cows, an altered EGF profile may not be a major cause of repeat breeding in Holstein heifers, and the peak EGF concentrations around day 3 may decrease even in fertile populations of multiparous dairy cows, but not in beef cows.     

Age-related Histological Findings in the Pineal Gland of Crl:CD(SD) Rats

To provide background data as the pathologic basis, the pineal glands of 190 male and 193 female Crl:CD(SD) rats at ages of 0–7, 51–58, 70–85 and 111 weeks were examined histologically in this study. Mineralization and fibrosis were common findings in the aged rats, whereas they were rarely found in the young ones; mineralization was present in 7, 44, 67 and 79% of males and in 0, 32, 67 and 79% in females, and fibrosis was present in 0, 29, 48 and 44% of males and 0, 18, 40 and 35% of females at ages of 0–7, 51–58, 70–85 and 111 weeks, respectively. Striated muscle fiber appeared regularly in the fibrosis region from 51–58 weeks of age when fibrosis increased, while the origin of this fiber remained unclear. Vacuolation of pineal cells also increased with age in both sexes, though the total incidence was low. There was a low incidence of lymphocytic infiltration in both sexes, but this was not related to age.     

Occurrence of Spontaneous Tumors in the Central Nervous System (CNS) of F344 and SD Rats

In order to accurately assess the carcinogenicity of chemicals with regard to rare tumors such as rat CNS tumors, sufficient information about spontaneous tumors are very important. This paper presents the data on the type, incidence and detected age of CNS tumors in F344/DuCrlCrlj (a total of 1363 males and 1363 females) and Crl:CD(SD) rats (a total of 1650 males and 1705 females) collected from in-house background data-collection studies and control groups of carcinogenicity studies at our laboratory, together with those previously reported in F344 and SD rats. The present data on F344/DuCrlCrlj rats (F344 rats) and Crl:CD(SD) rats (SD rats) clarified the following. (1) The incidences of all CNS tumors observed in F344 rats were less than 1%. (2) The incidences of malignant astrocytoma and granular cell tumor were higher in male SD rats than in female SD rats. (3) The incidences of astrocytoma and granular cell tumor were higher in SD rats than in F344 rats. (4) Among astrocytoma, oligodendroglioma and granular cell tumor, oligodendroglioma was detected at the youngest age, followed by astrocytoma, and ultimately, granular cell tumor developed in both strains. The incidences observed in our study were almost consistent with those previously reported in F344 and SD rats.     

An outbreak of rabbit hemorrhagic disease (RHD) caused by Lagovirus europaeus GI.2/rabbit hemorrhagic disease virus 2 (RHDV2) in Ehime, Japan

A total of ten 1–2-year-old rabbits died within 2 weeks at a facility in Ehime prefecture in May 2019. Necropsy revealed liver discoloration and fragility, hemorrhage of some organs and blood coagulation failure. On histopathologic examination, necrotizing hepatitis was a common finding, together with fibrin thrombi in the small vessels and hemorrhage in some organs. Rabbit hemorrhagic disease (RHD) virus gene was detected in liver samples, and viral particles of approximately 32 nm in diameter were found in the cytoplasm of degenerated hepatocytes by electron microscopy. Phylogenetic analysis based on the partial VP60 gene sequence classified it as Lagovirus europaeus GI.2/RHDV2. This is the first confirmed outbreak of RHD caused by globally emerging GI.2/RHDV2 in Japan.     

A multipronged approach for the detection of leptospirosis in captive sloth bears (Melursus ursinus) in Agra and Bannerghatta sloth bear rescue centers in India

Leptospirosis is an exacerbating factor responsible for the drastic decline of sloth bear population in India. In this study, a multipronged approach based on antigen detection using Polymerase Chain Reaction (PCR) employing G1/G2 and LigBF/LigBR primers, antibody detection using Microscopic Agglutination Test (MAT) and recombinant LigBCon1-5 antigen based Latex Agglutination Test (rLigBCon1-5 LAT), serum biochemistry using hepatic (serum glutamate oxalo acetic transaminase (SGOT) and serum glutamate pyruvic transaminase (SGPT) and renal biomarkers (blood urea nitrogen (BUN) and Creatinine) and gross/histopathological evidence in liver and kidneys were employed to investigate leptospirosis in captive sloth bears. A total of 133 serum samples collected from Agra (n=113) and Bannerghatta (n=20) sloth bear rescue centers were screened using MAT and rLigBCon1-5 LAT. A total of 87 and 78 sera tested positive by MAT and LAT respectively. Pyrogenes was the leading serovar obtained using MAT followed by Icterohaemorrhagiae, Javanica, Grippotyphosa, Canicola and Tarassovi. The relative sensitivity, specificity and accuracy of rLigBCon1-5 LAT in comparison to MAT were 89.66%, 100% and 93.23% respectively. PCR performed on hepatic and renal tissues showed amplicon of 285 and 219 base pairs for G1/G2 and LigBF/LigBR primers respectively. Gross evidence (icteric liver, severely engorged hepatic sinusoids, congested kidneys with necrotic white spots on sub capsular surface), histopathology (severe hepatic degeneration and tubulointerstitial nephritis) and elevated hepatic/renal biomarkers were suggestive of leptospirosis. This study suggests that rLigBCon1-5 LAT can be employed as a pen-side test for detecting leptospirosis in sloth bears.