Effects of altering diet carbohydrate profile and physical form on zoo-housed giraffe Giraffa camelopardalis reticulata.

Unlike wild giraffe that primarily consume low starch browse, the preference of zoo-housed giraffe for consuming supplemental feeds over forage could increase the risk of digestive disorders such as ruminal acidosis. Our objective was to evaluate the effects of modifying a supplemental feed's non-fibre carbohydrate profile and physical form on nutritional, behavioural, and blood measures of giraffe in a zoological setting. Six non-lactating, adult, female reticulated giraffes were used in a two-pen modified reversal study using two dietary treatments in seven 21-day periods with data collected on days 15-21. Dietary treatments were a control feed comprised of commercially available products used at the time as the giraffe feed (GF) and an unpelleted experimental feed (EF). On a dry matter basis, GF and EF, respectively, contained 17.0% and 17.4% crude protein, 14.2% and 1.5% starch, 14.9% and 21.3% ethanol-soluble carbohydrates, 22.9% and 26.0% acid detergent fibre (ADF) and 9.50% and 14.9% ND-soluble fibre (NDSF), with modulus of fineness values of 3.62 and 4.82. Supplemental feeds, alfalfa hay, salt, and water were available for ad libitum consumption. Significance was declared at p ≤ 0.05. Intakes of hay, supplemental feeds, and total feed did not differ by diet (p > 0.28), though intakes of starch (0.93 and 0.12 kg; p = 0.05) and ADF (1.83 and 2.23 kg; p = 0.04) differed between GF and EF respectively. Giraffe behaviour values (min/48 h) were greater with EF for total eating (p = 0.04); diets were not detected as different for engagement in oral stereotypes (GF = 433, EF = 318 min/48 h; p = 0.22). Blood glucose was higher on GF than EF (99.0 and 82.3 mg/dL; p = 0.03). The lower EF blood glucose value is more similar to ranges reported for domesticated ruminants. No differences were detected for changes in body weight or body condition score in the 21-day periods (p > 0.32). Modification of supplemental feed carbohydrate profile and physical form can influence behaviour and blood glucose values of zoo-housed giraffe.

The Many Hosts of Mycobacteria 9 (MHM9): A conference report.

The Many Hosts of Mycobacteria (MHM) meeting series brings together basic scientists, clinicians and veterinarians to promote robust discussion and dissemination of recent advances in our knowledge of numerous mycobacterial diseases, including human and bovine tuberculosis (TB), nontuberculous mycobacteria (NTM) infection, Hansen's disease (leprosy), Buruli ulcer and Johne's disease. The 9th MHM conference (MHM9) was held in July 2022 at The Ohio State University (OSU) and centered around the theme of "Confounders of Mycobacterial Disease." Confounders can and often do drive the transmission of mycobacterial diseases, as well as impact surveillance and treatment outcomes. Various confounders were presented and discussed at MHM9 including those that originate from the host (comorbidities and coinfections) as well as those arising from the environment (e.g., zoonotic exposures), economic inequality (e.g. healthcare disparities), stigma (a confounder of leprosy and TB for millennia), and historical neglect (a confounder in Native American Nations). This conference report summarizes select talks given at MHM9 highlighting recent research advances, as well as talks regarding the historic and ongoing impact of TB and other infectious diseases on Native American Nations, including those in Southwestern Alaska where the regional TB incidence rate is among the highest in the Western hemisphere.

PRELIMINARY EVALUATION OF SYMMETRIC DIMETHYLARGININE AS A BIOMARKER OF RENAL INSUFFICIENCY IN WILD AND REHABILITATED FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS).

Currently, there are limited antemortem tests available to evaluate renal function in Florida manatees (Trichechus manatus latirostris). Although few reports of renal pathology in manatees exist in the veterinary literature, debilitated animals that present to rehabilitation centers are frequently dehydrated, may have sustained renal trauma secondary to watercraft injury, and may experience ischemic events related to coagulation disorders leading to renal compromise. Clinicians remain limited to the analysis of blood urea nitrogen, creatinine levels, and urinalysis (if urine is obtained) to determine the extent of renal insufficiency, which may not accurately reflect renal function. This poses a diagnostic challenge for clinicians in discerning how critical renal compromise is to the animal's overall health and prognosis. For the first phase of this study, retrospective symmetric dimethylarginine (SDMA) values were determined from banked serum or plasma samples from 14 wild Florida manatees that had been collected while the animals were under rehabilitation in zoological institutions prior to their deaths. Values of SDMA for nine samples from eight manatees with known renal disease, as determined by histopathology, were compared to SDMA values for seven samples from six manatees with no reported renal lesions on histopathology. Values of SDMA from wild Florida manatees with known renal disease (mean 33.56 µg/dl ± 13.15, P= 0.017) were statistically significantly elevated when compared to SDMA values from manatees with no reported renal lesions (mean = 18.71 µg/dl ± 6.9) on histopathology. For the second phase of the study, serum or plasma samples were obtained from wild manatee populations from two geographically separate presumed-healthy wild manatee populations (n = 57). Although the upper limit was higher, serum SDMA concentrations from presumed-healthy wild manatees were comparable to those reported in small animal and equine medicine at 5.88-16.97 µg/dl.

Large Mammals Have More Powerful Antibacterial Defenses Than Expected from Their Metabolic Rates.

AbstractTerrestrial mammals span seven orders of magnitude in body size, ranging from the <2-g Etruscan pygmy shrew (Suncus etruscus) to the >3,900-kg African elephant (Loxodonta africana). Although body size profoundly affects the behavior, physiology, ecology, and evolution of species, how investment in functional immune defenses changes with body size across species is unknown. Here, we (1) developed a novel 12-point dilution curve approach to describe and compare antibacterial capacity against three bacterial species among >160 terrestrial species of mammals and (2) tested published predictions about the scaling of immune defenses. Our study focused on the safety factor hypothesis, which predicts that broad, early-acting immune defenses should scale hypermetrically with body mass. However, our three statistical approaches demonstrated that antibacterial activity in sera across mammals exhibits isometry; killing capacity did not change with body size across species. Intriguingly, this result indicates that the serum of a large mammal is less hospitable to bacteria than would be predicted by its metabolic rates. In other words, if metabolic rates underlie the rates of physiological reactions as postulated by the metabolic theory of ecology, large species should have disproportionately lower antibacterial capacity than small species, but they do not. These results have direct implications for effectively modeling the evolution of immune defenses and identifying potential reservoir hosts of pathogens.

EVALUATION OF THE PHARMACOKINETIC BEHAVIOR OF TULATHROMYCIN (DRAXXIN) IN FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS) UNDERGOING MEDICAL REHABILITATION.

Florida manatees (Trichechus manatus latirostris) frequently present to rehabilitation care facilities for various conditions, including boat strike trauma, cold stress syndrome, and brevetoxicosis. Throughout the course of treatment, antimicrobial use to treat respiratory disease is frequently warranted. To date, clinicians have extrapolated dosages based on established information available in bovine and equine medicine. The routes of administration, efficacy, and treatment intervals are considerations in dealing with critical wild animals. The use of tulathromycin, a triamilide antibiotic, has been studied in multiple domestic species of economic importance, including cattle, small ruminants, and swine, and has revealed efficacy against respiratory diseases. Given this information, this antibiotic has also been used in manatees with positive clinical outcomes. This study employed sparse sampling and evaluated banked plasma samples at various time intervals post-tulathromycin administration obtained during the clinical treatment course of nine animals during their rehabilitation. Preliminary pharmacokinetic analysis following administration of a single dose estimated a half-life of 33.75 h and volume of distribution per fraction absorbed (Vz/F = 4.29 L/kg). The pharmacokinetic behavior of tulathromycin in Florida manatees can be used to optimize dosage regimens in this species.

Serum Reference Intervals of Fat-Soluble Vitamins D and E in Wild Florida Manatees (Trichechus manatus latirostris) and Possible Implications for the Health of Manatees in Managed Care.

Serum levels of alpha-tocopherol (vitamin E) and 25-hydroxyvitamin D (vitamin D) were measured in 25 wild Florida manatees (Trichechus manatus latirostris) from Crystal River National Wildlife Refuge, Citrus County, Florida, US. The samples were collected during the 2017 and 2018 winter health assessments. Reference intervals for alpha-tocopherol were 0.15-3.2 µg/L with mean value of 0.76 µg/mL and for 25-hydroxyvitamin D were 4.3-23 nmol/L with a mean of 13.88 nmol/L. Four, long-term captive manatees and nine manatees in rehabilitation were available for comparisons. Alpha-tocopherol levels were within the established range for free-ranging manatees. Mean 25-hydroxyvitamin D levels in long-term captive and manatees in rehabilitation fell well outside the reference interval for free-ranging manatees, being six- to sevenfold higher. The absence of significant differences in alpha-tocopherol between wild and captive manatees may not have any significant direct clinical implications but may warrant an investigation into other antioxidant mechanisms in manatees. The elevated 25-hydroxyvitamin D levels seen in captivity were unexpected and, in a few individuals, may pose a health challenge. Calcium is known to be elevated in captive manatees as well; a close examination of a potential hypervitaminosis D and hypercalcemia may be warranted.

Trends of the Florida manatee (Trichechus manatus latirostris) rehabilitation admissions 1991-2017.

A retrospective study of admission data of 401 West Indian manatees (Trichechus manatus latirostris) presented to the David A. Straz Jr. Manatee Critical Care Center at ZooTampa at Lowry Park (ZooTampa) for rehabilitation from August 1991 through October 2017. Causes of admittance, location of rescue, gender, and age class were all recorded for each manatee admitted. Admittance categories as defined by the Florida Fish and Wildlife Conservation Commission (FWC) included watercraft collisions, natural causes, entanglement, entrapment, orphaned calves, captive born, mothers of rescued calves, calves of rescued mothers, human, and other. The admitted population was primarily from the southwest and northwest coasts and related waterways of Florida. The gender difference was relatively equivocal (54% female) while the adults comprised 79% of the admissions. The overall total admissions increased steadily over the study period as did the admissions for each individual categories of admission. Watercraft collisions and natural causes combined were 71% of all admissions for the entire study period and are the dominant causes of admission. Watercraft collisions are more likely to occur during May through October, whereas natural causes of admittance are more likely to occur between December and March. Rehabilitated manatees may reduce overall manatee mortality and can provide insight into population-based health concerns if evaluated appropriately. Future efforts can incorporate physical examination findings, hematology, biochemistry profiles, and ancillary diagnostic testing to continue to improve the individual welfare of this marine mammal in its natural range. Admissions data could also potentially serve the wider conservation and recovery efforts if it is proven that the data obtained is at least as informative as that obtained by the carcass salvage program. Limited conservation resources could then be re-directed as new challenges arise with the expanding population and potentially expanding range of this species.

The Effects of Body Mass on Immune Cell Concentrations of Mammals.

Theory predicts that body mass should affect the way organisms evolve and use immune defenses. We investigated the relationship between body mass and blood neutrophil and lymphocyte concentrations among more than 250 terrestrial mammalian species. We tested whether existing theories (e.g., protecton theory, immune system complexity, and rate of metabolism) accurately predicted the scaling of immune cell concentrations. We also evaluated the predictive power of body mass for these leukocyte concentrations compared to sociality, diet, life history, and phylogenetic relatedness. Phylogeny explained >70% of variation in both lymphocytes and neutrophils, and body mass appeared more informative than other interspecific trait variation. In the best-fit mass-only model, neutrophils scaled hypermetrically (b=0.11) with body mass, whereas lymphocytes scaled just shallow of isometrically. Extrapolating to total cell numbers, this exponent means that an African elephant circulates 13.3 million times the neutrophils of a house mouse, whereas their masses differ by only 250,000-fold. We hypothesize that such high neutrophil numbers might offset the (i) higher overall parasite exposure that large animals face and/or (ii) the higher relative replication capacities of pathogens to host cells.

Thromboelastography in wild Florida manatees (Trichechus manatus latirostris).

BACKGROUND: Thromboelastography (TEG) provides a comprehensive evaluation of blood clot formation. This test can be used to identify abnormalities in coagulation by assessing multiple aspects of the clotting cascade, including the speed of clot initiation and formation, clot strength, and ultimately fibrinolysis. Thromboembolic disease has been hypothesized to play a role in the pathophysiology of cold stress syndrome (CSS), an important cause of mortality in the threatened Florida manatee (Trichechus manatus latirostris). OBJECTIVES: The objective of this study was to establish thromboelastography RIs using the TEG 5000 with citrated whole blood samples and kaolin activation in wild, healthy manatees. METHODS: In December 2014 and January 2015, 29 wild manatees (17 male and 12 female) were blood sampled as part of the annual wild manatee health assessments organized by United States Geological Survey (USGS). TEG was performed using citrated kaolin-activated samples. RESULTS: The samples were obtained from manatees caught in Crystal River, Citrus County, and used to identify the mean ± SD of normal TEG parameters: R = reaction time 2.1 minutes (0.8), K = clot formation time 0.8 min (0), α angle = 83.1° (2), MA = maximum amplitude 75 mm (7.6), and LY30 = clot lysis 0.41% (0.68). No significant differences were found between manatee size, sex, or time between sampling and running the test. CONCLUSIONS: Manatee TEG parameters demonstrate a relatively hypercoagulable condition when compared to other mammals. This information will facilitate detection of changes in hemostasis during injury and disease and provide a valuable reference range.

Early fetal sexing in the rhinoceros by detection of male-specific genes in maternal serum.

Genetic sexing of animals with long gestation time benefits the management of captive populations. Here, X and Y chromosome-specific primers, based on equine gene sequencing data, were developed and tested on captive rhinoceroses (10 males, 20 females) representing four species (Diceros bicornis, Certaotherium simum simum, Rhinoceros unicornis, and Dicerorhinus sumatrensis). The Y chromosome-specific primer set targeted SRY (Sex-determining region Y), and amplified a 177-bp product following PCR of DNA extracted from males, but not females, of all species. A primer set based on the equine AMEL (Amelogenin) gene resulted in a 232-bp product following PCR of all rhinoceros species. These gene-specific primer sets were then evaluated for their ability to determine gender in cell-free DNA from rhinoceros serum. Modifications to the original extraction and PCR protocols were required to obtain sufficient DNA quantities from serum, and both DNA yield and PCR amplification were substantially reduced or absent following multiple freeze-thaw cycles of serum. When fresh serum from 14 pregnant rhinoceroses (ultimately bearing seven male and seven female calves), representing four species at different stages of gestation (Days 61-490), were probed in a PCR-based assay, an accuracy of 71% was achieved for male-specific gene detection of SRY, which improved to 100% by including a reamplification step into the protocol. Such early sex determination should be a valuable tool for current management practices as well as future assisted reproduction of rhinoceroses.

Bioaugmentation of the anaerobic digestion of food waste by dungs of herbivore, carnivore, and omnivore zoo animals.

The potential improvement of biomethanation of food waste (FW) by adding dung of herbivore (giraffe, llama, koala), carnivore (tiger), and omnivore (sloth bear) animals to anaerobic sludge (AnS) was investigated. Adding 30% giraffe, sloth bear or koala dung to the AnS inoculum yielded, respectively, a 11.17 (±4.51), 10.10 (±1.23), and 1.41 (±0.56)% higher biomethane production, as compared to the control (FW with solely AnS). The highest biomethane production of 564.00 (±3.88) ml CH4/gVSadded obtained with 30% giraffe dung and 70% AnS was attributed to a higher solubilization of proteins (6.96 ± 2.76%) and recalcitrant carbohydrates (344.85 ± 54.31 mg/L as compared to zero). The biomethanation process could have been stimulated by the microorganisms or enzymes newly introduced, and/or the trace elements (Ni, Zn, and Co) present in the giraffe dung. These results indicate that bioaugmentation with zoo animals dung is worthy of further investigation as a strategy for improving the biomethane recovery from organic wastes.

Identifying coagulopathies in the pathophysiology of cold stress syndrome in the Florida manatee Trichechus manatus latirostris.

Cold stress syndrome (CSS) in the Florida manatee Trichechus manatus latirostris has been defined as morbidity and mortality resulting from prolonged exposure to water temperatures <20°C. The pathophysiology is described as multifactorial, involving nutritional, immunological and metabolic disturbances; however, the exact mechanisms are unknown. We hypothesized that thromboembolic complications contribute to the pathophysiology of CSS in addition to the previously described factors. During the winter of 2014-2015, 10 Florida manatees with clinical signs of CSS were presented to Lowry Park Zoo, Tampa, FL, USA. Thromboelastography (TEG) and coagulation panels were performed at admission. In addition, coagulation panel data from 23 retrospective CSS cases were included in the analyses. There were numerous differences between mean values of TEG and coagulation parameters for healthy manatees and those for CSS cases. Among TEG parameters, reaction time (R), clot formation time (K) and percentage of clot lysed after 30 min (LY30) values were significantly different (p < 0.05) between the 2 groups. CSS cases also had significantly higher mean D-dimer concentration and coagulation factor XI activity, prolonged mean activated partial thromboplastin time (aPTT) and significantly decreased mean antithrombin activity. These combined abnormalities include clinicopathologic criteria of disseminated intravascular coagulation, indicating an increased risk of thromboembolic disease associated with manatee CSS.

PROPOSAL AND APPLICATION OF A NOVEL DISSEMINATED INTRAVASCULAR COAGULATION SCORING SYSTEM IN THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS).

Disseminated intravascular coagulopathy (DIC) is an acquired disorder of hemostasis resulting in activation of the coagulation and fibrinolytic pathways. It is reported secondarily to multiple disease processes and can be associated with increased mortality. Previous research at Tampa's Lowry Park Zoo (LPZ) demonstrated that Florida manatees ( Trichechus manatus latirostris) with cold stress syndrome (CSS) demonstrated thromboembolic disease. The object of this retrospective study was to establish the presence and clinical relevance of DIC in Florida manatees admitted to LPZ for rehabilitation from 07 March 2010 to 15 August 2015. A coagulation panel, including prothrombin time, partial thromboplastin time, platelet count, fibrinogen level, and D-dimer level was used to diagnose DIC. There were 100 cases identified in the study period: 35 trauma, 43 CSS, 17 secondary to harmful algae blooms (HAB), and five miscellaneous. Manatees with CSS had the highest incidence of DIC with 24 of 43 cases (56%) affected, followed by trauma with 18 of 35 cases (52%) affected. None of the manatees with HAB were found to have DIC. Manatees that developed DIC during rehabilitation or when DIC progressed did not survive. Due to the clinical implications of DIC, identifying its presence and recognizing its severity could improve clinical outcomes by enabling more intensive treatment protocols.

Normal Hemostatic Profiles and Coagulation Factors in Healthy Free-Living Florida Manatees ( Trichechus manatus latirostris).

Hemostatic disorders presumptively play an important role in the pathophysiology of several important disease conditions in the Florida manatee ( Trichechus manatus latirostris). Prior to pursuing such clinical implications, it is essential to establish normal hemostatic profiles in clinically healthy animals. During annual health assessments of free-living manatees organized by the US Geological Survey, blood samples were collected from 12 healthy animals from the Atlantic coast and 28 from the Gulf of Mexico coast of Florida, with body lengths of 210-324 cm. The following analyses were performed on citrated plasma: prothrombin (PT), partial thromboplastin time (PTT), and concentrations of fibrinogen, D-dimers, and coagulation factors VII, VIII, IX, X, XI, and XII. Compared to other mammalian species, manatees had short PT (9.2±1.5 s) and PTT (10.7±0.5 s), fibrinogen was 369±78.7 mg/dL, antithrombin III was 132±11%, and D-dimer was 142±122 ng/mL. Baseline concentrations for the listed coagulation factors were established. When comparing coagulation factors between locations, Atlantic coast manatees had significantly higher factors VIII, IX, and X than did Gulf Coast manatees. This finding may reflect differences in water salinity, diet, or genetics. There were no differences in coagulation factors when among sexes and sizes. These baselines for hemostatic profiles and coagulation factors in healthy free-living manatees lay the foundation for diagnosis and future research of hemostatic disorders and contribute to understanding their role in the pathophysiology of manatees affected by various diseases.

REPRODUCTIVE NEOPLASMS IN WILD AND LONG-TERM CAPTIVE FEMALE FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS).

Few reports of neoplastic diseases in manatees exist in the veterinary literature. This case series presents reproductive neoplasia noted in eight wild and long-term captive female Florida manatees (Trichechus manatus latirostris) obtained through carcass recovery and animal rehabilitation programs between April 2009 and May 2014. All cases were evaluated histologically, and diagnoses of uterine carcinoma (n = 1), granulosa cell tumor (n = 2), ovarian adnexal tumor (n = 1), and leiomyoma (n = 5) were made. The underlying cause of tumor development and effects on reproductive success is currently unknown, but possible asymmetric reproductive aging and/or a correlation between obesity and reproductive disorder in long-term nonreproductive female manatees are of interest and warrant further investigation.

MANAGEMENT OF OMPHALOPHLEBITIS AND UMBILICAL HERNIA IN THREE NEONATAL GIRAFFE (GIRAFFA CAMELOPARDALIS).

Umbilical disorders, including omphalophlebitis, omphaloarteritis, external umbilical abscesses, urachal abscesses, patent urachus, and umbilical hernias, represent a significant challenge to the health and well-being of a neonate. The three neonatal giraffe (Giraffa camelopardalis) in this report were evaluated for umbilical swellings. Two developed omphalophlebitis, and one had an uncomplicated umbilical hernia. Omphalophlebitis is an inflammation and/or infection of the umbilical vein. Giraffe calves with a failure of passive transfer may be predisposed and should be thoroughly evaluated for the condition. Umbilical hernias result from a failure of the umbilical ring to close after parturition or from malformation of the umbilical ring during embryogenesis. These problems were surgically corrected for all three individuals, although one died due to postsurgical complications. The risks involved include anesthetic complications, surgical dehiscence, and maternal rejection. Early detection and surgical intervention are recommended for the correction of omphalophlebitis and umbilical hernias in neonatal giraffe.

Establishment of reference values for various coagulation tests in healthy Florida manatees (Trichechus manatus latirostris) and evaluation of coagulation in debilitated manatees during rehabilitation.

OBJECTIVE: To establish reference ranges for coagulation parameters in healthy Florida manatees (Trichechus manatus latirostris) and compare results with those for debilitated manatees undergoing treatment at a rehabilitation facility. DESIGN: Prospective study. ANIMALS: 29 healthy manatees and 45 debilitated manatees with various diseases. PROCEDURES: Manatees considered healthy on the basis of results of physical examination, CBC, and serum biochemical analysis underwent coagulation testing including measurement of prothrombin time, partial thromboplastin time, D-dimer concentration, platelet count, and fibrinogen concentration to establish reference ranges. For comparison, a group of manatees undergoing rehabilitation was also tested, and the results were compared. Thromboelastography was also performed on some animals. RESULTS: Values for D-dimer concentration were significantly higher in debilitated versus healthy animals. There was no significant difference for prothrombin time, partial thromboplastin time, platelet count, or fibrinogen concentration between groups. Thromboelastography was performed on 8 healthy animals. CONCLUSIONS AND CLINICAL RELEVANCE: Reference ranges were established for various tests of coagulation that may assist clinicians during the initial evaluation and rehabilitation of Florida manatees. Future research to evaluate the effect of specific disease processes on the coagulation cascade is recommended.

ESTABLISHMENT OF ECHOCARDIOGRAPHIC PARAMETERS OF CLINICALLY HEALTHY FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS).

A standardized echocardiographic technique was recently established for the Florida manatee (Trichechus manatus latirostris). There are no available published data on normal echocardiographic parameters in any Sirenian species. The purpose of this study was to report reference parameters for various echocardiographic measurements. These parameters are intended to serve as a comparison for future research into the prevalence of cardiac diseases in the manatee and to aid in diagnosing animals with suspected cardiac disease in rehabilitation facilities. Annual health assessments of free-ranging manatees in Crystal River National Wildlife Refuge, Florida, and pre-release health assessments of rehabilitated manatees at Tampa's Lowry Park Zoo permitted comparison of echocardiographic measurements in adult (n=14), subadult (n=7), and calf (n=8) animals under manual restraint.

Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress.

The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida's southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p<0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the wild impacts some immune function components, and thus, overall health, in the Florida manatee.

Recurrence of hyperprolactinemia and continuation of ovarian acyclicity in captive African elephants (Loxodonta africana) treated with cabergoline.

Hyperprolactinemia is associated with reproductive acyclicity in zoo African elephants (Loxodonta africana) and may contribute to the non-self-sustainability of the captive population in North America. It is a common cause of infertility in women and other mammals and can be treated with the dopamine agonist cabergoline. The objectives of this study were to assess prolactin responses to cabergoline treatment in hyperprolactinemic, acyclic African elephants and to determine the subsequent impact on ovarian cyclic activity. Five elephants, diagnosed as hyperprolactinemic (>11 ng/ml prolactin) and acyclic (maintenance of baseline progestagens for at least 1 yr), were treated with 1-2 mg cabergoline orally twice weekly for 16-82 wk. Cabergoline reduced (P < 0.05) serum prolactin concentrations during the treatment period compared to pretreatment levels in four of five elephants (11.5 +/- 3.2 vs. 9.1 +/- 3.4 ng/ml; 20.3 +/- 16.7 vs. 7.9 +/- 9.8 ng/ml; 26.4 +/- 15.0 vs. 6.8 +/- 1.5 ng/ml; 42.2 +/- 22.6 vs. 18.6 +/- 8.9 ng/ml). However, none of the females resumed ovarian cyclicity based on serum progestagen analyses up to 1 yr posttreatment. In addition, within 1 to 6 wk after cessation of oral cabergoline, serum prolactin concentrations returned to concentrations that were as high as or higher than before treatment (P < 0.05). One elephant that exhibited the highest pretreatment prolactin concentration (75.2 +/- 10.5 ng/ml) did not respond to cabergoline and maintained elevated levels throughout the study. Thus, oral cabergoline administration reduced prolactin concentrations in elephants with hyperprolactinemia, but there was no resumption of ovarian cyclicity, and a significant prolactin rebound effect was observed. It is possible that higher doses or longer treatment intervals may be required for cabergoline treatment to result in permanent suppression of prolactin secretion and to mitigate associated ovarian cycle problems.