About

Chris Byron, DVM, MS, DACVS, is the Department Head of the Department of Large Animal Clinical Sciences at the Virginia-Maryland College of Veterinary Medicine, Virginia Tech. He has been serving as an Associate Professor in Large Animal Surgery since 2014 and became department head in 2022. His research interests include the pathobiology and treatment of osteoarthritis in horses, as well as multidisciplinary research in the development of cancer treatments and the identification of surgeon performance metrics. Dr. Byron earned his Bachelor of Science from Cornell University in 1994, his Doctor of Veterinary Medicine from Cornell University in 1998, and his Master of Science in Large Animal Clinical Sciences from Michigan State University in 2002. He is board-certified by the American College of Veterinary Surgeons since 2003. His professional experience includes roles as a resident in equine surgery at Michigan State University, an intern at Rood and Riddle Equine Hospital, assistant professor at the University of Illinois, surgeon at Ruffian Equine Medical Center, and assistant scientific editor for the American Veterinary Medical Association. His career has been dedicated to equine surgery and large animal clinical sciences, with a focus on advancing surgical techniques and treatment options for large animals.

Research topics

• Medicine
• Internal medicine
• Pathology
• Biology
• Chemistry
• Anesthesia
• Medical physics
• Pharmacology
• Immunology
• Cell biology
• Surgery

Selected publications

• Presumptive Lyme disease-associated eosinophilic synovitis in a horse

  Journal of Equine Veterinary Science · 2025-05-06 · 1 citations

  article
  PublisherDOI

• Comparison of Gait Characteristics for Horses Without Shoes, with Steel Shoes, and with Aluminum Shoes

  Animals · 2025-08-13

  articleOpen accessSenior authorCorresponding

  Differences in horseshoe materials may have effects on gait that could change perceived esthetic qualities. Objective information regarding effects of shoeing on gait characteristics of horses is scant. The aim of this study was to determine differences in gait characteristics for horses under various experimental shoeing conditions (barefoot, aluminum shoes, steel shoes) on two surfaces (asphalt and soft footing) using body- and hoof-mounted sensors. We hypothesized that shoeing would affect hoof arc height during early (arc height a) and late (arc height b) swing phases but would not affect other gait variables. Twelve healthy, adult, client-owned horses were evaluated at a trot on asphalt and soft footing under the three experimental shoeing conditions. No significant (p < 0.05) effects of shoeing were detected for gait symmetry (Q score), mediolateral hoof deviation, stride length, or midstance, breakover, swing, and landing stride phase times. Hoof arc height a was significantly (p < 0.001) lower for aluminum versus steel shoes for right and left forelimbs on asphalt and soft footing. Hoof arc height b was significantly higher for aluminum versus steel shoes on soft footing for left (p < 0.001) and right (p = 0.02) forelimbs. Findings indicate that shoe weights affect early and late swing phase hoof heights differently. Further investigation is warranted to determine whether measured hoof arc height changes affect subjective esthetics of gait.

  PublisherOA PDFDOI

• Abstract 7236: First successful engraftment of human pancreatic cancer cells in an immunocompromised porcine model to test tumor ablation by high-frequency irreversible electroporation (H-FIRE)

  Cancer Research · 2025-04-21

  article

  Abstract Pancreatic tumor is difficult to treat due to late diagnosis, critical tumor location, limited surgical options, and high metastatic potential. High-frequency irreversible electroporation (H-FIRE) is a non-thermal ablation technique that uses high-voltage electric pulses to create permanent nanopores in cell membranes, disrupting homeostasis and inducing cell death. This study established the feasibility of using H-FIRE to ablate pancreatic tumors in an immunocompromised porcine model were RAG2/IL2RG double knockout pigs. Panc1 human pancreatic cancer cells were orthotopically injected into the pancreas of these pigs. 3 weeks post-injection, successful tumor engraftment and growth were observed during treatment. We successfully accessed and treated the tumors using H-FIRE, with clear ablation zones and preservation of surrounding tissue confirmed by histopathology. The treatment also showed minimal local muscle contraction. This study demonstrated the first robust large-animal model of H-FIRE-treated human pancreatic cancer with safety and efficacy. Future work will explore the potential of these immunocompromised porcine models for developing advanced therapeutic strategies to enhance tumor ablation by H-FIRE. Citation Format: Manali Powar, Tamalika Paul, Edward Jacobs, Sherrie Clark-Deener, Christopher Byron, Sheryl Coutermarsh-Ott, Katie Orr, Maxx Steinmann, levente Gal, Cassandra Poole, Carley Elliott, Mackenzie Woolls, Madeline Mott, Julio Arroyo, Zaid Salameh, Hannah Ivester, Rafael V. Davalos, Irving Coy Allen. First successful engraftment of human pancreatic cancer cells in an immunocompromised porcine model to test tumor ablation by high-frequency irreversible electroporation (H-FIRE) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7236.

  PublisherDOI

• Abstract 1456: First successful engraftment of human liver cancer cell line in highly robust immunocompromised porcine model to test the tumor ablation efficacy by histotripsy

  Cancer Research · 2024-03-22 · 1 citations

  article

  Abstract Liver tumor, commonly called Hepatocellular carcinoma(HCC), is the most common type of primary liver malignancy. It is the fourth leading cause of cancer-related deaths. Late diagnosis, location of the tumor, tumor burden, and metastases makes liver tumor very challenging to treat by liver transplantation, surgical procedures, and other ablation techniques like cryoablation and thermal ablation. Also, the absence of a preclinical animal model makes it challenging to develop and explore the feasibility of treatment modalities. Histotripsy is a non-invasive, non-ionizing, non-thermal, image-guided focused ultrasound ablation treatment method that uses high-pressure pulses to create acoustic cavitation, a “bubble cloud,” at the target. The bubble cloud expands and collapses, which ablates the tissue into an acellular homogenate. Pigs are ideal animal models as they closely resemble human anatomy and are significant in improving the translation to human patients. This study aimed to establish the feasibility of successfully ablating liver tumors by histotripsy using an immunocompromised porcine model to generate HepG2 human liver cancer cell line tumors in the liver of the immunocompromised pigs. The orthotopic porcine model was established using RAG2/IL2RG double knockout immunocompromised pigs. HepG2 cells were injected orthotopically into the liver of immunocompromised pigs. Three weeks after the injections, CT images and necropsy indicated successful engraftment and growth of liver tumors in the pigs. The ultrasound images and post-histotripsy treatment histology images showed confirmed ablation zones in the liver. Therefore, in conclusion, our preliminary results in the study could demonstrate, for the first time, a highly robust model of human liver cancer in a large animal model. Soon, we plan to conduct more such studies and explore all the possible utilities of these immunocompromised porcine models to develop therapeutic strategies to increase the efficacy of liver tumor ablation by histotripsy. Citation Format: Tamalika Paul, Khan M. Imran, Jessica Gannon, Brie Trusiano, Kristin Eden, Hannah Ivester, Madeline Mott, Manali Powar, Michael Edwards, Christopher Byron, Sherrie Clark-Deener, Kiho Lee, Eli Vlaisavljevich, Irving Coy Allen. First successful engraftment of human liver cancer cell line in highly robust immunocompromised porcine model to test the tumor ablation efficacy by histotripsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1456.

  PublisherDOI

• Equine Local Anesthetic and Analgesic Techniques

  2024-06-21 · 2 citations

  otherSenior author

  A variety of local and regional anesthetic techniques may be used to provide anesthesia and analgesia for surgical procedures in equine patients. Unlike many species, local anesthetic techniques in horses may additionally be utilized for the diagnosis and/or localization of musculoskeletal pain. This chapter provides an overview of local and regional anesthetic techniques that may be used to provide anesthesia and analgesia for surgical procedures, as well as the localization and temporary relief of musculoskeletal pain. While ultrasound-guided regional anesthesia is discussed, the reader is referred elsewhere for the most current description of specific techniques.

  PublisherDOI

• Lyme Disease-Associated Eosinophilic Synovitis in a Horse

  SSRN Electronic Journal · 2024-01-01

  preprintOpen access
  PublisherDOI

• Technique for guttural pouch bead removal using a novel three‐dimensional (<scp>3D)</scp>‐printed instrument

  Veterinary Surgery · 2024-07-26 · 1 citations

  article

  OBJECTIVE: The aim of the present study was to determine if a three-dimensional (3D)-printed instrument technique would improve lavage removal of plastic beads (guttural pouch [GP] chondroid mimics) through a dorsal pharyngeal recess (DPR) fenestration. We hypothesized that using a 3D-printed instrument placed through the DPR fenestration would remove more beads, reduce lavage time and incur less soft tissue damage than using a lavage tube control or instrument placement through the salpingopharyngeal ostium (SPO). STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: A total of 30 cadaveric equine heads. METHODS: DPR fenestration was performed using transendoscopic laser and 50 plastic 12 mm beads were placed into one GP of horse heads. Four removal procedures using a 3D-printed instrument or lavage tube control placed through the DPR fenestration or the SPO were compared. Number of beads removed and number of 2-min lavage cycles to recover ≥96% of beads or three consecutive no-yield cycles were recorded. Endoscopic soft tissue damage was graded. Data were compared by generalized estimating equations (GEE) model and Fisher's exact test (p < .05). RESULTS: More beads (median 48 beads; range 0-49) were removed faster (median 24 beads/cycle; range 12-50) using the 3D-printed instrument compared to control (median 6 beads; range 0-29, 0.66 beads/cycle, range 0-49). There was no difference between total beads removed or removal speed between placement sites. There was no difference in soft tissue damage between procedures. CONCLUSION: Our 3D-printed instrument enabled efficient plastic bead removal. CLINICAL SIGNIFICANCE: DPR fenestration and use of our 3D-printed instrument represents an alternative to current chondroid removal techniques, warranting investigation in clinical cases.

  PublisherDOI

• Intra-articular bone marrow mononuclear cell therapy improves lameness from naturally occurring equine osteoarthritis

  Frontiers in Veterinary Science · 2023-10-09 · 2 citations

  articleOpen access

  Osteoarthritis (OA) can be debilitating and is related to impaired resolution of synovial inflammation. Current treatments offer temporary relief of clinical signs, but have potentially deleterious side effects. Bone marrow mononuclear cells (BMNC) are a rich source of macrophage progenitors that have the ability to reduce OA symptoms in people and inflammation in experimentally-induced synovitis in horses. The objective of this study was to evaluate the ability of intra-articular BMNC therapy to improve clinical signs of naturally occurring equine OA. Horses presenting with clinical and radiographic evidence of moderate OA in a single joint were randomly assigned to 1 of 3 treatment groups: saline (negative control), triamcinolone (positive control), or BMNC (treatment group). Lameness was evaluated subjectively and objectively, joint circumference measured, and synovial fluid collected for cytology and growth factor/cytokine quantification at 0, 7, and 21 days post-injection. Data were analyzed using General Estimating Equations with significance set at p &amp;lt; 0.05. There were no adverse effects noted in any treatment group. There was a significant increase in synovial fluid total nucleated cell count in the BMNC-treated group on day 7 (median 440; range 20–1920 cells/uL) compared to day 0. Mononuclear cells were the predominant cell type across treatments at all time points. Joint circumference decreased significantly in the BMNC-treated group from days 7 to 21 and was significantly lower at day 21 in the BMNC-treated group compared to the saline-treated group. Median objective lameness improved significantly in the BMNC group between days 7 and 21. GM-CSF, IL-1ra, IGF-1, and TNF-α were below detectable limits and IL-6, IL-1β, FGF-2 were detectable in a limited number of synovial fluid samples. Inconsistent and limited differences were detected over time and between treatment groups for synovial fluid PGE 2 , SDF-1, MCP-1 and IL-10. Decreased lameness and joint circumference, coupled with a lack of adverse effects following BMNC treatment, support a larger clinical trial using BMNC therapy to treat OA in horses.

  PublisherOA PDFDOI

• Pharmacokinetics, clinical efficacy and safety of acetaminophen (paracetamol) in adult horses with naturally occurring chronic lameness

  Equine Veterinary Journal · 2023-06-07 · 6 citations

  article

  Abstract Background Acetaminophen is used clinically in horses with musculoskeletal pain; however, no studies have been performed in horses with chronic lameness. Objectives To determine the pharmacokinetics, safety and efficacy of chronic dosing of acetaminophen in horses with naturally occurring chronic lameness. Study design Longitudinal. Methods Twelve adult horses with chronic lameness were treated with acetaminophen (30 mg/kg PO) every 12 h for 21 days. Plasma concentrations of acetaminophen were analysed on days 7 and 21 via LC–MS/MS and noncompartmental pharmacokinetic analysis. Lameness was evaluated by body‐mounted inertial sensor (BMIS) and 10‐point subjective lameness score on day 21 and compared to untreated baseline evaluation on day 35. Clinicopathological analysis ( n = 12), hepatic biopsy ( n = 6) and gastroscopy ( n = 6) were evaluated on days −1 and 22. Results Maximum plasma acetaminophen concentration ( C max ) was 20.83 ± 10.25 μg/mL at time ( T max ) 0.40 ± 0.22 h on day 7. The C max on day 21 was 17.33 ± 6.91 μg/mL with a T max of 0.67 ± 0.26 h. Subjective lameness scores significantly improved at 2 and 4 h post‐treatment; Significant percent improvement was detected in PD max for horses with hindlimb lameness at 1, 2 and 8 h post‐treatment. There were no significant differences in gastroscopy or hepatic biopsy scores between days −1 and 22. Main limitations Small sample size, multi‐limb lameness of varying severity and aetiology, lack of intermediary lameness evaluation. Conclusions In horses with naturally occurring chronic lameness, acetaminophen at 30 mg/kg produced a transient improvement in subjective lameness and BMIS evaluation. Acetaminophen may not be effective as a monotherapy. Acetaminophen was safe following 21 days of 30 mg/kg PO every 12 h, with no evidence of clinically significant changes in clinicopathological analysis, hepatic biopsy or gastric ulceration scores.

  PublisherDOI

• Physical Activity Profiles among Patients Admitted with Acute Exacerbations of Chronic Obstructive Pulmonary Disease

  Journal of Clinical Medicine · 2023-07-26 · 1 citations

  articleOpen access1st author

  People with hospitalised acute exacerbations of chronic obstructive pulmonary disease (AECOPD) exhibit low levels of physical activity (PA) and increased risks of future exacerbations. While methods to objectively measure and express PA are established for people with stable COPD, less clarity exists for people during AECOPD. Further, the relationship between PA during AECOPD and clinically relevant outcomes remains uncertain. The purpose of the study was to evaluate how much PA (step count and intensity) people accumulate during hospitalised AECOPDs, and the effect of accumulated inpatient PA (expressed via differing metrics) on length of stay (LOS), PA recovery, and readmission risk. This study was a secondary analysis of prospective observational cohort data collected with Actigraph wActiSleep-BT devices from patients with AECOPD in a Melbourne hospital from 2016 to 2018. Step counts and PA intensity throughout the hospital admission and at one-month follow-up were collected and analysed. Sixty-eight participants were recruited for inpatient measurement, and 51 were retained for follow-up. There were no significant changes in step count or intensity across the inpatient days, but 33/51 (65%) of participants demonstrated a clinically meaningful improvement in steps per day from 3817.0 to 6173.7 at follow-up. Participants spent most time sedentary and in light PA, with both PA metrics demonstrating significant influences on LOS and follow-up PA intensity, but with generally low explanatory power (R2 value range 7–22%). Those who had LOS &lt; 5 days spent significantly less time sedentary and more time in light PA than those with LOS ≥ 5 days (p &lt; 0.001 for both). Time spent sedentary or in light PA appears to be the most promising metric to associate with clinically relevant outcomes related to recovery following AECOPD. These findings can inform future clinical practice for the evaluation of inpatient PA to better establish its role in the clinical management of patients with AECOPD.

  PublisherOA PDFDOI

Frequent coauthors

• Stephen R. Werre

  Virginia–Maryland College of Veterinary Medicine

  23 shared

• Craig Mosley

  18 shared

• Allison A. Stewart

  University of Illinois Urbana-Champaign

  15 shared

• Sophie H. Bogers

  Virginia–Maryland College of Veterinary Medicine

  14 shared

• Bruno Carvalho Menarim

  14 shared

• Linda A. Dahlgren

  Virginia Tech

  13 shared

• Harold C. McKenzie

  Virginia–Maryland College of Veterinary Medicine

  10 shared

• Cynthia M. Trim

  University of Georgia

  9 shared