About

Lorin D. Warnick, DVM, DACVPM, is the Austin O. Hooey Dean of Veterinary Medicine at Cornell University College of Veterinary Medicine, where he also serves as a Professor of Ambulatory and Production Medicine. His research focuses on the epidemiology of Salmonella infections and antimicrobial resistance of enteric bacteria of importance in domestic animals and humans. He has taught herd health, population medicine, and health economics in pre-clinical courses and was actively involved in Cornell University's response to the COVID-19 pandemic, participating in research related to SARS-CoV-2 diagnostic testing and the occurrence of COVID-19 on campus. Dr. Warnick earned his B.S. in Microbiology from Brigham Young University, his DVM with High Distinction from Colorado State University, and his Ph.D. in Veterinary Medicine with an Epidemiology Concentration and a minor in Statistics from Cornell University. His professional experience includes roles at the Virginia-Maryland Regional College of Veterinary Medicine and Cornell University, where he has held positions from Assistant Professor to Dean. He is a Diplomate of the American College of Veterinary Preventive Medicine and has received numerous honors, including membership in Phi Zeta and Phi Kappa Phi, as well as the American Veterinary Epidemiology Society's Honorary Diploma.

Research topics

• Medicine
• Internal medicine
• Virology

Selected publications

• Evaluation of Short-Term Stall Size Housing on the Behavior and Welfare of Domestic Horses (Equus caballus)

  Journal of the American Association for Laboratory Animal Science · 2026-04-01

  article

  Single-stall housing is a common system used for horses in various settings, including racing stables, riding schools, teaching and research facilities. Adequate stall space is necessary for horses to lie down and make postural adjustments, both of which are essential for equine rest and welfare. The Guide for the Care and Use of Laboratory Animals recommends a stall size of 144 ft2. However, not all stalls meet this size requirement, and there is limited literature supporting its use in terms of animal welfare. This study used a crossover design to compare behavioral and physiologic variables indicative of welfare of horses housed in the standard recommended 144-ft2 stall compared with a smaller stall (136 ft2) to determine whether the smaller stalls affected horses' welfare and behavior. Eight horses (1,380-1,640 lb) were paired with preferred associates resulting in 4 pairs. One horse from each pair was randomly assigned to be housed in either the standard stall (144 ft2) or the smaller stall (136 ft2) for 4 days (from Monday morning through Friday morning), while the paired horse was housed in the opposite-sized stall. After this initial stall period, all horses were turned out to pasture for 9 days before being housed in the alternate-sized stall for an additional 4 days. Hay consumption, fecal output, and serum cortisol were quantified daily. Movement and duration of recumbency were measured with an accelerometer, and continuous video recordings of all horses were obtained while housed in the stalls (total of ∼96 hours per horse per stall condition). Behavioral variables (resting, locomotion, standing, consummatory, elimination, and stereotypic behavior) were scored every 5 minutes from the recordings and compared between stall conditions. Although several measures changed across days in both stall conditions, stall size did not affect the horses' hay consumption, fecal output, or cortisol concentrations, nor the duration of sternal or lateral recumbency as determined by accelerometer data. However, the duration of walking recorded by the accelerometer different between the 2 stall sizes with horses spending more time walking in the smaller stall (136 ft2). Analysis of video recordings also found no difference in percentage of time spent in sternal or lateral recumbency, rolling, standing, stand resting, walking, eating, or drinking. In conclusion, time budgets, food intake, fecal output, and cortisol concentrations were similar in horses housed in the standard-sized stall (144 ft2) compared with the smaller stall (136 ft2), suggesting that the reduced stall size did not result in observable changes in equine behavior or physiologic welfare indicators compared with the standard-sized stall.

  PublisherDOI

• The role of veterinary diagnostic laboratories during COVID-19 response in the United States

  PLoS ONE · 2024-06-25 · 4 citations

  articleOpen accessSenior authorCorresponding

  Robust testing capacity was necessary for public health agencies to respond to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 19 (COVID-19) pandemic. As the nation faced the need for robust testing capacity, it became necessary to use all possible resources. In many cases, veterinary diagnostic laboratories rose to meet this demand because these facilities routinely perform high throughput diagnostic testing of large animal populations and are typically familiar with pathogens of high pandemic concern. In this study, we evaluated the impact of veterinary diagnostic laboratories in the United States on SARS-CoV-2 testing. Results of surveys, semi-structured interviews, and analysis of publicly available information showed that veterinary diagnostic laboratories had a substantial impact on human health through population-level testing in the COVID-19 response, supporting timely and informed public health interventions. This success was not without significant hurdles, as many participating veterinary diagnostic laboratories experienced restriction in their response due to difficulties obtaining the Clinical Laboratory Improvement Amendments (CLIA) certification required to conduct human diagnostic testing. Our results point out the importance of reducing hurdles before the next major public health emergency to enhance access to testing resources overall and to ultimately improve population health.

  PublisherOA PDFDOI

• The Cornell COVID-19 Testing Laboratory: A Model to High-Capacity Testing Hubs for Infectious Disease Emergency Response and Preparedness

  Preprints.org · 2023-06-12 · 1 citations

  preprintOpen access

  The unprecedented COVID-19 pandemic posed major challenges to local, regional, and global economies and health systems, and fast clinical diagnostic workflows were urgently needed to contain the spread of SARS-CoV-2. Here, we describe the platform and workflow established at the Cornell COVID-19 Testing Laboratory (CCTL) for high-throughput testing of clinical samples from the university and the surrounding community. This workflow enabled efficient and rapid detection, and successful control of SARS-CoV-2 infection on campus and its surrounding communities. Our cost-effective and fully automated workflow enabled testing of over 8,000 pooled samples per day and provided results for over 2 million samples. Automation of time- and effort-intensive sample processing steps such as accessioning and pooling increased laboratory efficiency. Customized software applications were developed to track and store samples, deconvolute positive pools, track and report results and for workflow integration from sample receipt to result reporting. Additionally, quality control dashboards and turn-around time tracking applications were built to monitor assay and laboratory performance. As infectious disease outbreaks pose a constant threat to both human and animal health, the highly effective workflow implemented at CCTL could be modeled to establish regional high-capacity testing hubs for infectious disease preparedness and emergency response.

  PublisherOA PDFDOI

• The role of veterinary diagnostic laboratories during COVID-19 response in the United States

  medRxiv · 2023-12-06

  preprintOpen accessSenior authorCorresponding

  Abstract Robust testing capacity was necessary for public health agencies to respond to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 19 (COVID-19) pandemic. As the nation faced the need for robust testing capacity, it became necessary to use all possible resources. In many cases, veterinary diagnostic laboratories rose to meet this demand because these facilities routinely perform high throughput diagnostic testing of large animal populations and are typically familiar with pathogens of high pandemic concern. In this study, we evaluated the impact of veterinary diagnostic laboratories in the United States on SARS-CoV-2 testing. Results of surveys, semi-structured interviews, and analysis of publicly available information showed that veterinary diagnostic laboratories had a substantial impact on human health through population-level testing in the COVID-19 response, supporting timely and informed public health interventions. This success was not without significant hurdles, as many participating veterinary diagnostic laboratories experienced restriction in their response due to difficulties obtaining the Clinical Laboratory Improvement Amendments (CLIA) certification required to conduct human diagnostic testing. Our results point out the importance of reducing hurdles before the next major public health emergency to enhance access to testing resources overall and to ultimately improve population health.

  PublisherOA PDFDOI

• The Cornell COVID-19 Testing Laboratory: A Model to High-Capacity Testing Hubs for Infectious Disease Emergency Response and Preparedness

  Viruses · 2023-07-15 · 5 citations

  articleOpen access

  The unprecedented COVID-19 pandemic posed major challenges to local, regional, and global economies and health systems, and fast clinical diagnostic workflows were urgently needed to contain the spread of SARS-CoV-2. Here, we describe the platform and workflow established at the Cornell COVID-19 Testing Laboratory (CCTL) for the high-throughput testing of clinical samples from the university and the surrounding community. This workflow enabled efficient and rapid detection and the successful control of SARS-CoV-2 infection on campus and its surrounding communities. Our cost-effective and fully automated workflow enabled the testing of over 8000 pooled samples per day and provided results for over 2 million samples. The automation of time- and effort-intensive sample processing steps such as accessioning and pooling increased laboratory efficiency. Customized software applications were developed to track and store samples, deconvolute positive pools, track and report results, and for workflow integration from sample receipt to result reporting. Additionally, quality control dashboards and turnaround-time tracking applications were built to monitor assay and laboratory performance. As infectious disease outbreaks pose a constant threat to both human and animal health, the highly effective workflow implemented at CCTL could be modeled to establish regional high-capacity testing hubs for infectious disease preparedness and emergency response.

  PublisherOA PDFDOI

• Genomics at Cornell University College of Veterinary Medicine

  American Journal of Veterinary Research · 2023-07-13 · 1 citations

  articleOpen access
  PublisherOA PDFDOI

• Routine Surveillance and Vaccination on a University Campus During the Spread of the SARS-CoV-2 Omicron Variant

  JAMA Network Open · 2022 · 10 citations

  Senior authorCorresponding
  • Virology
  • Medicine
  • Internal medicine

  This case series study of COVID-19 data from a US university examines the effectiveness of various vaccination, testing, and surveillance measures to mitigate spread of the Omicron variant.

  PublisherOA PDFDOI

• Case–control study to identify risk factors for SARS‐CoV‐2 infection among university students in the northeastern USA

  Transboundary and Emerging Diseases · 2022-06-10 · 9 citations

  articleOpen accessSenior author

  Curbing the coronavirus disease 2019 (COVID-19) pandemic requires a thorough understanding of risk factors for transmission of SARS-CoV-2, the etiologic agent. Institutions of higher education present unique challenges for controlling disease spread because of features inherent to these settings. Our objective was to determine risk factors for SARS-CoV-2 infection among a university student population in the northeastern USA during the spring and fall 2021 semesters, using the case-control study design. Cases were defined as students with a newly diagnosed SARS-CoV-2 infection detected either through the robust PCR-based surveillance testing program on campus or through healthcare testing if symptoms compatible with COVID-19 were present. Controls were defined as students with negative SARS-CoV-2 status, based on consistently negative PCR results at the time of selection. A comprehensive questionnaire was administered to each student enrolled in the study, covering a broad range of campus life activities. A total of 446 cases and 1,185 controls were included in this study. Multivariable logistic regression analysis showed that recent party attendance (adjusted OR = 2.3, p < .0001), recently visiting a bar (aOR = 1.6, p = .007), living in a campus residence hall (aOR = 1.6, p = .001), fraternity/sorority membership (aOR = 1.8, p = .002), and recent travel (aOR = 1.3, p = .04) were associated with being a COVID-19 case. Having an on-campus job was negatively associated with being a COVID-19 case (aOR = 0.6, p = .0003). Among cases, the most commonly reported symptoms were cough (43.9%), fatigue (38.1%) and sore throat (30.3%). These findings can be used to inform the development of COVID-19 mitigation strategies and public health outreach efforts in university settings, thus reducing SARS-CoV-2 transmission among students and helping to preserve the vital education and research missions of these institutions.

  PublisherOA PDFDOI

• Integrated Surveillance System for Controlling COVID-19 on a University Campus, 2020‒2021

  American Journal of Public Health · 2022-06-21 · 2 citations

  articleOpen access

  To minimize the impacts of COVID-19 and to keep campus open, Cornell University’s Ithaca, NY, campus implemented a comprehensive process to monitor COVID-19 spread, support prevention practices, and assess early warning indicators linked to knowledge, behaviors, and attitudes of campus community members. The integrated surveillance approach informed leadership and allowed for prompt adjustments to university policies and practices through evidence-based decisions. This approach enhanced healthy behaviors and promoted the well-being and safety of all community members. (Am J Public Health. 2022;112(7):980–984. https://doi.org/10.2105/AJPH.2022.306838 )

  PublisherOA PDFDOI

• Characterization and comparison of the microbiomes and resistomes of colostrum from selectively treated dry cows

  Journal of Dairy Science · 2021-11-09 · 26 citations

  articleOpen access

  Professionals in animal agriculture promote prudent use of antimicrobials to address public and animal health concerns, such as reduction of antimicrobial residues and antimicrobial resistance (AMR) in products. Few studies evaluate the effect of selective dry-cow therapy on preservation of the milk microbiome or the profile of AMR genes (the resistome) present at freshening. Our objectives were to characterize and compare the microbiomes and resistomes in the colostrum of cows with low somatic cell count that were treated or not treated with intramammary cephapirin benzathine at dry-off. From a larger parent study, cows on a New York dairy farm eligible for dry-off and with histories of somatic cell counts ≤200,000 cells/mL were enrolled to this study (n = 307). Cows were randomly assigned to receive an intramammary antimicrobial and external teat sealant (ABXTS) or sealant only (TS) at dry-off. Composite colostrum samples taken within 4 h of freshening, and quarter milk samples taken at 1 to 7 d in milk were subjected to aerobic culture. The DNA extraction was performed on colostrum from cows with culture-negative samples (ABXTS = 43; TS = 33). The DNA from cows of the same treatment group and parity were pooled (26 pools; ABXTS = 12; TS = 14) for 16S rRNA metagenomic sequencing. Separately, the resistome was captured using a custom RNA bait library for target-enriched sequencing. Sequencing reads were aligned to taxonomic and AMR databases to characterize the microbiome and resistome, respectively. The R statistical program was used to tabulate abundances and to analyze differences in diversity measures and in composition between treatment groups. In the microbiome, the most abundant phyla were Firmicutes (68%), Proteobacteria (23%), Actinobacteria (4%), and Bacteroidetes (3%). Shannon and richness diversity means were 0.93 and 14.7 for ABXTS and 0.94 and 13.1 for TS, respectively. Using analysis of similarities (ANOSIM), overall microbiome composition was found to be similar between treatment groups at the phylum (ANOSIM R = 0.005), class (ANOSIM R = 0.04), and order (ANOSIM R = -0.04) levels. In the resistome, we identified AMR gene accessions associated with 14 unique mechanisms of resistance across 9 different drug classes in 14 samples (TS = 9, ABXTS = 5). The majority of reads aligned to gene accessions that confer resistance to aminoglycoside (TS = ABXTS each 35% abundance), tetracycline (TS = 22%, ABXTS = 54%), and β-lactam classes (TS = 15%, ABXTS = 12%). Shannon diversity means for AMR class and mechanism, respectively, were 0.66 and 0.69 for TS and 0.19 and 0.19 for ABXTS. Resistome richness diversity means for class and mechanism were 3.1 and 3.4 for TS and 1.4 and 1.4 for ABXTS. Finally, resistome composition was similar between groups at the class (ANOSIM R = -0.20) and mechanism levels (ANOSIM R = 0.01). Although no critical differences were found between treatment groups regarding their microbiome or resistome composition in this study, a larger sample size, deeper sequencing, and additional methodology is needed to identify more subtle differences, such as between lower-abundance features.

  PublisherOA PDFDOI

Frequent coauthors

• Julie D. Siler

  Cornell University

  97 shared

• Yrjo T. Gröhn

  83 shared

• Kevin J. Cummings

  Cornell University

  73 shared

• Martin Wiedmann

  Cornell University

  65 shared

• Margaret A. Davis

  50 shared

• Emily Wright

  44 shared

• C.L. Guard

  44 shared

• Karin Hoelzer

  43 shared

Education

• PhD

  Cornell University

  1994

• DVM

  Colorado State University

  1988

• B.S.

  Brigham Young University

  1983

Awards & honors

• Phi Zeta Veterinary Honor Society, 1987
• Phi Kappa Phi Honor Society, 1988
• Graduate Research Assistantship, 1991-1993
• Honorary Diploma, July 16, 2018; American Veterinary Epidemi…
• "One Cornell Award", Cornell COVID-19 Testing Laboratory Lea…