Mason C. Jager DVM, PhD, DACVP

Primary Investigator

Dr. Mason Jager serves as an Assistant Professor in the Department of Population Medicine and Diagnostic Sciences at Cornell University. His journey began in Connecticut, where he grew up and attended the University of Connecticut, earning a BS in Pathobiology in 2004. Following his passion for veterinary medicine, he moved to Ithaca in 2008 to attend the Cornell University College of Veterinary Medicine. After obtaining his DVM degree in 2012, Dr. Jager gained practical experience as an associate veterinarian at a large companion animal hospital in Middletown, CT. His dedication to advancing veterinary science led him back to Cornell, where he completed a residency in veterinary anatomic pathology. Driven by curiosity and a desire to contribute to the field, he pursued a PhD in Biomedical and Biological Sciences, focusing on viral pathogenesis, which he successfully completed in 2022. As faculty in the section of Anatomic Pathology, Dr. Jager performs diagnostic services at the NYS Animal Health Diagnostic Center while mentoring residents and veterinary students. Within the Pathology Discovery Laboratory at the CVM, Dr. Jager leads research exploring host-pathogen interactions, particularly focusing on viral pathogenesis. Employing a diverse array of methodologies spanning traditional pathology, molecular virology, and cell biology, the lab investigates virus distribution, tissue tropism, and crucial host factors impacting disease progression. A central focus of the lab’s work is unraveling the intricacies of viral hepatitis pathogenesis, aiming to unlock insights that promise to shape future therapeutic approaches and clinical interventions, thus contributing significantly to the advancement of veterinary pathology and virology, with broader implications for animal and human health. Fun fact: Mason was a finalist for NASA’s astronaut program in 2025!

What do you like to do outside of the lab? Woodworking, photography, volunteer firefighter

Samantha Shallop, BS

Technician III & MS Stuent (EDP)

I am a dual Cellular & Molecular Neuroscience and Biology major with a background in neurodevelopment. I graduated with a Distinction in Neuroscience within the Honors Program from Temple University in 2020- complete with a mock, solo graduation walk at home. Since then, I’ve worked across molecular, virological, and neurological systems, from investigating cortical organization in Tuberous Sclerosis Complex to characterizing abnormal neurodevelopment in Duchenne Muscular Dystrophy. Currently, I work as a Technician III and Lab Manager at Cornell University’s Discovery Pathology Lab, where I have the privilege of working with a variety of pathogens. My personal research involves the investigation of how animal parvoviruses respond to DNA damage, and how the DNA Damage Response (DDR) pathway may be involved in replication dynamics. How do I balance working full-time and being a grad student, you ask? Caffeine… lots of it. And the occasional (interrupted) book break.

What do you like to do outside of the lab?

Outside the lab, I’m most often found cozied up with a latte and a good book (currently Anxious People by Fredrik Backman and a re-listen of Dungeon Crawler Carl by Matt Dinniman). I enjoy cooking and eating—though not necessarily in that order—and playing board games and reminding people it’s their turn- specifically in that order. When the weather cooperates, I like to adventure with my very agile blind dog, whether that means hiking or attempting yoga around him on my mat.

Rachel Dufour, DVM (she/her/hers)

BBS PhD Student

Dr. Rachel Dufour is a veterinary graduate from LSU Vet Med ’24. While originally from Memphis, New Orleans is her second home. (She misses the food and culture terribly) She earned degrees in chemistry and psychology from Loyola University New Orleans in 2017. During her undergraduate studies she conducted research on both gold nanoparticles, for the chemistry degree, and in interpersonal closeness, for her psychology degree. This multidisciplinary focus of study drove her to veterinary medicine, where she feels care for people, animals, and science easily marry. After working as a veterinary assistant she enrolled in veterinary school.

During her DVM training, she developed a deep interest in infectious diseases and viral pathogenesis. She conducted transcriptional research on herpesviruses at both LSU and Cornell, which made the decision to return to Cornell for her PhD an easy one. She is now a T32 NIH Fellow in the Jager Lab, where she studies viral and toxin pathogenesis and their impact on oncogenesis.

What do you like to do outside of the lab?

Outside of the lab she can be found wondering around looking at birds, on roller skates, or curled up with a good book.

James (Jimmy) Quinlan

Undergraduate Student Researcher

I am a sophomore in the College of Arts and Sciences majoring in Biological Sciences and minoring in Biomedical Engineering. I have an interest in attending medical school in the future with interests in emergency medicine, virology, and oncology.

Lab Alumni

Brooklin Hunt (she/her)

Rotation DVM/PhD Student

I am a combined DVM/PhD student interested in epidemiology and pathology in livestock and wildlife species. During my rotation, I worked with Dr Jager and Dr Joy Tomlinson to analyze clinical records from donkeys and horses treated at the Cornell University Hospital for Animals. We compared liver enzyme and serum biochemistry panels between the donkeys and horses to understand how liver disease may present differently in donkeys. Additionally, Dr. Jager and I are working together to create a histology atlas of Jamaican fruit bat tissues. If I’m not in the lab, I’m usually lifting or running, cooking, or doing something outside like fishing or hiking!

Joshua Farris (He/Him)

DVM Student Researcher (Future Pathologist)

Hi, I’m Josh! I’m a 4th year veterinary student interested in pathology and infectious disease. I love exploring how microbes interact with their hosts and how that knowledge can improve diagnostics and animal health. Outside of school and the lab, you can usually find me weightlifting or spending time with my cat. Fun Fact: I played the trumpet for many years, including performing at a Memphis Grizzlies game.

Elizabeth Williams Louie, DVM, DACVIM (LAIM)

Rotation DVM seeking PhD Student

Currently: PhD Candidate in Katharyn Mitchell’s Large Animal Cardiovascular Lab

My name is Beth Williams Louie. I grew up in Northern California in a small rural town. I attended Oregon State for undergrad and then UC Davis for veterinary school. I then completed a 1-year equine focused internship at Littleton Equine in Colorado. It was there I developed an interest in equine cardiology. Following my internship, I returned to UC Davis for a 3-year residency in large animal Internal Medicine. I continued cultivating my passion for equine cardiology there through several research projects and clinical experience. I am now a PhD in Katharyn Mitchell’s Large Animal Cardiovascular Lab investigating myocardial dysfunction and risk factors for arrhythmias in large animals. Outside of work I enjoy hiking, reading, horseback riding, and spending time with my husband and dogs.

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