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Greg Lewbart

Professor of Aquatic Animal Medicine

CVM Main Building C295

Publications

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Grants

Date: 06/01/21 - 10/01/21
Amount: $5,000.00
Funding Agencies: Triangle Community Foundation

Glucocorticoids are products of the stress response that can cause immune suppression and inhibit wound healing. For hospitalized patients, a rise in glucocorticoids could prolong recovery time or even worsen the patient’s prognosis. The relationship between elevated glucocorticoids and survivorship in critically ill humans, dogs, and horses has been well established in the literature. While it is known that wildlife in captivity experience stress and elevated glucocorticoids, little work has been done to investigate how glucocorticoids could reflect survivorship in hospitalized wildlife. Eastern box turtles (EBT, Terrapene carolina carolina) commonly present to wildlife hospitals for traumatic injuries, as they are likely to have increased exposure to people and vehicles due to their terrestrial lifestyle. The Turtle Rescue Team (TRT) at North Carolina State University’s College of Veterinary Medicine regularly sees EBTs, as they routinely make up about 50% of annual intakes. The purpose of this proposed project is to measure corticosterone in EBTs admitted to the TRT for traumatic injuries to determine if plasma corticosterone concentrations can be used as a prognostic indicator in turtles. Using blood samples collected from 60 EBTs at 0 hours, 24 hours, and weekly for up to four weeks, serum corticosterone levels will be analyzed in relation to injury severity, serum lactate, packed cell volume, blood smear leukograms, and survivorship during hospitalization. This project will improve our understanding of the stress response as a prognostic indicator in wild turtles, which can help wildlife rehabilitators and veterinary staff target critical patients for more intensive care.

Date: 06/01/21 - 9/01/21
Amount: $5,000.00
Funding Agencies: Morris Animal Foundation

The purpose of this proposed project is to measure corticosterone in EBTs admitted to the TRT for traumatic injuries to determine if plasma corticosterone concentrations can be used as a prognostic indicator in turtles. Blood samples will be collected from 60 EBTs on the day of admission (day 0), at 24 hours, and weekly for up to four weeks. For all sample collections, blood will be collected within 3 minutes of approaching the turtle’s enclosure in order to avoid handling-induced elevation of corticosterone [19]. In addition to measurement of plasma corticosterone using commercially available ELISA kits, lactate, packed cell volume (PCV) and blood smears will also be analyzed. On admission, each EBT will be given a numeric “Triage Score” based on the severity of injuries, activity level, and presence of reflexes [20]. This score will be updated each time a blood sample is collected from an EBT (at 24 hours and weekly for up to four weeks). Corticosterone concentrations and other hematological parameters at day 0 and at 24 hours will be compared to survivorship at 30 days, and the weekly measurements will be used to assess how the parameters change over time during hospitalization.

Date: 05/16/20 - 8/15/20
Amount: $5,000.00
Funding Agencies: Morris Animal Foundation

The proposed project will investigate the consequences of competition and hybridization with the invasive Red-eared slider (T. s. elegans) on native Yellow-bellied slider (T. s. scripta) health and population genetics in North Carolina. The first aim of this study will be to perform health assessments, including body condition scoring, bloodwork, and fecal parasite assessment on native Yellow-bellied sliders in locations (ponds) with high and low contact with introduced red-eared sliders. The presence of Red-eared sliders is predicted to induce stress in native Yellow-bellied sliders due to increased competition, increased turtle density, as well as consequences of hybridization (both genetic and due to contact during mating). We predict that the results of these health evaluations will reveal that Yellow-bellied sliders in ponds with high red-eared slider populations will have (1) lower body condition scores due to increased food stress, (2) lower total blood protein (indication of stress), (3) lower calcium (indication of poor nutrition), (4) increased percentage of heterophils (indication of stress), and (5) greater intestinal parasite load than Yellow-bellied sliders in ponds with fewer or no red-eared sliders. Health assessments will also be performed on red-eared sliders and red-eared/yellow-bellied hybrids in areas of high contact. We predict that if Red-eared sliders are indeed competitively superior, health scores will be poorer for Yellow-bellied sliders than for the Red-eared sliders in areas of contact. Assessing these parameters in hybrids will also allow us to better understand the viability of F1 crosses to determine how hybridization might affect Yellow-bellied slider populations. If these assays reveal lower stress, better nutrition and/or lower parasite load in hybrids than in the Yellow-bellied sliders, the latter might be at higher risk of being competitively excluded by the former. All individual turtles included in health assessments will be genotyped using next-generation sequencing techniques (genotyping-by-sequencing The results of this genotyping project will provide insight into the mating behavior of F1 hybrids to determine whether Yellow-bellied sliders are at risk of “genetic swamping” from introgression with hybrids. Pairing the health analyses proposed here with this genotype data will ensure confidence in the identification of Red-eared and Yellow-bellied sliders and their hybrids.

Date: 06/01/17 - 5/31/20
Amount: $95,000.00
Funding Agencies: NC Department of Natural and Cultural Resources

To provide medical, surgical, and preventive care support to the collection animals of the North Carolina Museum of Natural Sciences. Said care will include physical examination, diagnostic techniques, the administration of medications, surgery, and necropsy examination when appropriate.

Date: 06/01/16 - 9/30/17
Amount: $5,000.00
Funding Agencies: Triangle Community Foundation

Eastern box turtles (Terrapene carolina carolina) are an important, and iconic, reptile species native to North Carolina and much of the Eastern United States. Unique among turtles, these animals spend their entire lives on land, inhabiting woodlands and grasslands. Eastern box turtles are also the most common species presented to the Turtle Rescue Team (TRT) at the North Carolina State University College of Veterinary Medicine. An organization operated by veterinary students, the TRT sees over 300 wild reptiles and amphibians every year. Turtles present to the TRT for a variety of reasons including vehicular trauma, aural abscessation, and upper respiratory infections. Many of these turtles require antibiotic therapy prior to release, but the TRT is hampered by a limited selection of antimicrobial drugs and insufficient data on what the body does to the drug once administered (pharmacokinetics) to guide appropriate dosing schedules. A useful antimicrobial drug in this setting must be (1) injectable, (2) inexpensive, (3) effective against the bacteria causing the problem, and (4) be absorbed and work appropriately in turtles. I will be studying the fourth requirement of these criteria - understanding how effectively turtles absorb and metabolize a common class of antibiotics, fluoroquinolones. This is important in determining the clinical utility of these drugs in turtles, and Eastern box turtles specifically. For this study I have selected injectable fluoroquinolones (enrofloxacin / ciprofloxacin) because they already meet the first three criteria. Optimizing the relationship of how the drugs work in the body, and how the drugs affect the bacteria, will improve treatment outcomes and potentially reduce selection for antibiotic-resistant bacteria. I will examine the efficacy of administering either a dilute solution of enrofloxacin, or the human injectable formulation of ciprofloxacin. Current protocol uses enrofloxacin as a subcutaneous injection that must be diluted with five parts saline due to the caustic nature of the drug. Ciprofloxacin is more active than enrofloxacin against the bacteria of concern and will be potentially easier to administer. If successful, this pharmacokinetics study would greatly optimize the use of these antimicrobials in Eastern box turtles. We have designed this study to take advantage of the unique opportunity of utilizing patients that are presented to the TRT.

Date: 07/01/14 - 6/30/17
Amount: $65,000.00
Funding Agencies: NC Dept. of Natural & Cultural Resources formerly NC Dept of Env. & Natural Resources (DENR)

To provide medical, surgical, and preventive care to a collection of confiscated reptiles housed at the North Carolina Museum of Natural Sciences. Said care will include physical examination, diagnostic techniques, the administration of medications, surgery, and necropsy examination when appropriate.

Date: 06/01/16 - 12/31/16
Amount: $5,000.00
Funding Agencies: Triangle Community Foundation

Turtle populations, especially eastern box turtles (Terrapene carolina), are in decline due to habitat fragmentation, vehicular mortality, and the pet trade (Adamovicz L., et. al. 2015). Human populations continue to expand, pushing into critical habitats for native wildlife. As human developments grow, so does the need for wildlife medicine. With many turtle species living and reproducing for upwards of 50 years in the wild, each individual returned to the population has a significant impact on species conservation. The Turtle Rescue Team (TRT) at North Carolina State University College of Veterinary Medicine receives approximately 350 sick and injured chelonians annually. Many of these turtles present with traumatic injuries and severe viral infections, commonly including vehicular trauma, dog attacks, fish hook foreign bodies, aural abscesses, and viral respiratory infections. Treatment plans are developed based on physical examination findings and radiographs if warranted; routine blood work is not commonly performed. These methods can be somewhat subjective. Reliable blood gas, hematological and biochemical analysis provide a more definitive assessment of physiologic status, and consequently development of a more effective treatment plan. These values can also help determine the prognosis of our patients, which would allow for us to proceed with the most humane option upon arrival.

Date: 10/01/15 - 9/30/16
Amount: $130,000.00
Funding Agencies: NC Dept. of Natural & Cultural Resources formerly NC Dept of Env. & Natural Resources (DENR)

The NCSU CVM EMC faculty are interested in discovering and developing improved ways to deliver health care and management for aquarium collections as part of our research mission, and the education and training of aquatic veterinarians as a component of the education mission of the university.

Date: 02/01/16 - 4/30/16
Amount: $1,000.00
Funding Agencies: American Veterinary Medical Foundation

Our college has just admitted the most diverse DVM class in our history. 28% of our incoming first-year class self-identify as an underrepresented minority. This program will help us to sustain the positive cultural changes that we are experiencing. Our college is now providing the NCBI program for all CVM faculty, staff and students, with workshops being offered this Fall.

Date: 04/01/15 - 11/30/15
Amount: $3,700.00
Funding Agencies: American Association of Zoo Veterinarians (AAZV)

Sea urchins play a vital role in marine ecosystems providing a food source for predators and regulating algae growth. Fluctuations in predator populations that decrease predation pressure can increase sea urchin populations and subsequently increase grazing of algae and kelp forests. Alternatively, mass mortality events of sea urchins can cause marked increases in algae. Numerous sea urchin mass mortality events documented across the world’s oceans have been attributed to a variety of infectious and non-infectious causes. Various bacterial species including the Vibrio and Pseudoaltermonas genera have been isolated during specific mass mortality events. Sea urchins are commonly kept in public and private aquariums, where they may be subject to introduction of pathogenic microorganisms or opportunistic infections and could benefit from antimicrobial treatment. There is a lack of pharmacokinetic studies and information regarding appropriate antimicrobial agents, doses, and treatment protocols for this group of invertebrates. The objective of this study is to evaluate and compare the effects of enrofloxacin and its active metabolite ciprofloxacin in the green sea urchin (Strongylocentrotus droebachiensis) following intracoelomic and bath administration. The study also aims to evaluate hemolymph as a sample for pharmacokinetic studies in this species.


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