Kelly B. Tisher, DVM

Kelly B. Tisher, DVM is the current President and Treasurer of Littleton Equine Medical Center. He received his undergraduate degree at South Dakota State University where he served as  Student Body President. Dr. Tisher earned his Doctor of Veterinary Medicine from the University of Minnesota 1994. At Littleton Equine Medical Center, his focuses are Sports Medicine, Lameness and Magnetic Resonance Imaging (MRI). When not at the clinic, you will find him enjoying the great outdoors  with his daughter, Maggie, who tends to their dog, cats and chickens. Learn More

Scott Toppin, DVM, DABVP

Born in Metamora, Michigan, Dr. Toppin moved to Colorado in 1994, and joined the practice as an Intern that same year.  After the internship, he moved to Arizona and worked at Southwest Equine Hospital for four years.  During that time, he developed an interest in internal medicine and emergency surgery.  Dr. Toppin returned to Littleton Equine Medical Center in 1999, and has remained at the clinic since that time.

Dr. Toppin grew up with quarter horses that were supposed to race, but instead made really fast 4-H and field hunters.  He was a groom for a hunter/jumper trainer during high school and summers during college.

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G. Marvin Beeman, DVM


Born in Highlands Ranch, Colorado, Dr. Beeman has been active in the equine world from early childhood to present.  He has greatly contributed to the education of equestrians across the United States and internationally.  An innovator in the equestrian world, Dr. Beeman has been presented with many awards.

He has been an equine practitioner for over 57 years, and his specialties include a variety of lameness and musculoskeletal issues.

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Charles D. Vail, DVM


 Born in Denver, Colorado, Dr. Vail has been a prominent figure in the Thoroughbred and Quarter Horse racing industry since 1958.  He has been with Littleton Equine Medical Center since 1960. Dr. Vail also served as the track veterinarian for Centennial Race Track from 1962-1963, and currently serves as a Colorado Racing Commissioner.

When not immersed in the equine world, he spends time with his wife, Jeannie, son & daughter, four grandchildren. Learn More

Terry D. Swanson, DVM


Dr. Swanson was raised on a cattle ranch 20 miles east of Chugwater, Wyoming.  This was the beginning of his respect and appreciation of horse, especially the equine athlete.

He has enjoyed many phases of equine veterinary medicine including surgery and reproduction but has honed his expertise, by demand and interest, to diagnosis and management of lameness of the performance horse.  He has attained wide respect not only locally but nationally as well.

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Dustin V. Devine, DVM, MS, DACVS

A native of Weatherford, Oklahoma, Dr. Devine grew up around quarter horses and has been an equine veterinary practitioner since 2002. Prior to joining LEqMC, Dr. Devine held the position of Assistant Professor of Equine Surgery for his alma mater.  While at Oklahoma State, he taught several courses including Clinical Anatomy, Advanced Equine Medicine, Surgery, and managed the Equine Surgery Clinical Rotation.  Additionally, he served as examiner for the Clinical Proficiency exam in Equine Surgery.  He has written several abstracts, published numerous research papers for well-known medical journals, and has presented at veterinary symposiums and annual conferences around the nation. Learn More

Peter Rakestraw, MA, VMD, DACVS

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Dr. Rakestraw graduated from the University of Pennsylvania, College of Veterinary Medicine in 1986. From there he completed a one year internship at the Littleton Large Animal Hospital and continued his training as a Large Animal Surgery Resident at Cornell University, in Ithaca New York. He finished his surgery residency in 1991 and was asked to stay on at Cornell for a year as a “Lecturer” in the Large Animal Surgery Section. From there he went to Washington State University for a year as a Lecturer in Equine and Food Animal Surgery. Dr. Rakestraw passed his surgery boards and became a Diplomate of the American College of Veterinary Surgery in 1991. During his time as a resident at Cornell he developed a research interest in Equine Upper Airway and Equine Colic. His presentation and research study on Laryngeal Hemiplegia won the outstanding large animal clinical presentation award at the resident’s completion at the 1990 ACVS annual conference.  Learn more

Shannon J. Murray, DVM, MS, DACVS

Dr. Murray grew up in New Hampshire. Most recently, she has moved from Rhinebeck, in the Hudson Valley of NY, to the Littleton area. She is very excited to explore her new ‘backyard’!

Dr. Murray earned her undergraduate degree at Pomona College in Claremont, CA where she majored in Neuroscience. She attended the University of California, Davis School of Veterinary Medicine. After earning her doctorate, she completed a rigorous surgical and medical internship at Rood and Riddle Equine Hospital in Lexington, KY, where she worked extensively with horses of all ages in the Thoroughbred industry. Dr. Murray then completed her residency in Equine Surgery at The Ohio State University, where she became skilled in all facets of equine surgery (elective and emergency), sports medicine and diagnostic imaging, including nuclear scintigraphy and CT. She particularly enjoys the challenges of gastrointestinal ‘colic’ surgery, and has a special interest in emergencies and critical care. Learn More

Kathleen Mullen, DVM, MS, DACVIM

Dr. Katie Mullen grew up in Evergreen and spent her summers on her family’s cattle ranch near Paonia. A good deal of her childhood was spent trying to catch her horse, a flea-bitten gray Arabian gelding. When convinced to be caught, he served as a sure-footed ranch horse or dressage show horse depending on the day.

Dr. Mullen spent many years taking advantage of the numerous educational opportunities at Cornell University. The long, cold, gray winters of Ithaca, NY served as the ideal location to study Animal Science (B.S. with Honors), Agricultural Economics (M.S.) and Veterinary Medicine (DVM and Large Animal Internal Medicine Residency). Before obtaining her veterinary degree, Dr. Mullen was as a trade economist in Washington, D.C. However, a yearning to be closer to the horses she had always loved, motivated her to apply to veterinary school.  Learn More

Lois Toll, DVM

Born in Denver, Colorado, Dr. Toll joined our practice as a Veterinary Assistant in 1981.  After going back to school, she became a Veterinarian in 1992. Dr Toll’s equine experience started with the 4H Pony Club.  Her personal experience includes; eventing, fox hunting, combined driving and mountain pack trips.  She also had the opportunity to work for a hunter/jumper trainer.

Dr. Toll prides herself on being a well rounded veterinarian, and enjoys the challenge of lameness and general practice here at Littleton Equine Medical Center.  Learn More

Ronald J. Streeter, DVM

Dr. Ronald Streeter (Ron) was born in Ponca City, Oklahoma, and raised on a nearby farm.

Dr. Streeter and his wife Kathi, who is also his assistant, enjoy general practice. They pride themselves in offering a sound and practical approach to ambulatory practice. They feel fortunate to be able to refer more difficult cases to the clinic for specialized care while remaining a part of their patient’s care. Learn More

Jessica Dunbar, DVM

Born in Rochester, Michigan, Dr. Dunbar grew up riding in the United States Pony Club and went on to compete in eventing through college. Dr. Dunbar completed her Bachelor of Science degree at the University of Illinois-Urbana-Champaign and her Doctor of Veterinary Medicine at the University of Illinois.

After graduating from the University of Illinois, Dr. Dunbar did a year long internship at Wisconsin Equine Clinic and Hospital then came to work here at Littleton Equine Medical Center in 2006. Dr. Dunbar’s areas of focus here at Littleton Equine are Dentistry and Chiropractic, but she enjoys all aspects of equine practice. Learn More

David N. Lori, DVM, MBA

Dr. Lori was born and raised on a Morgan Horse Farm in Tunbridge, Vermont, and grew up 1 mile from the first Morgan horse in the breed’s history.  He attended high school in Scotland, and traveled much of Europe, before returning to the United States to attend college.

After completing his undergraduate degree, Dr. Lori explored the opportunity of medical school and worked as a research associate at Dartmouth Medical, along with taking classes.  It was at this time that Dr. Lori elected to pursue veterinary school. Learn More

William French, DVM

Dr. French is a 5th generation Colorado native and grew up in Fort Collins. He started riding as a small child in both English and Western disciplines. After high school, he worked on guest ranches during summers and pursued a bachelor’s degree in Equine Science at Colorado State University.

While at Colorado State University, Dr. French competed on the horse judging team, was a teacher’s assistant for packing and outfitting, and completed research in Equine Reproduction. Dr. French was admitted to Colorado State University’s Veterinary School where his passion for the horse was furthered. After veterinary school, Dr. French completed his internship at Littleton Equine Medical Center, rotating through surgery, emergency and field services. Learn More

Rebecca S. Dietz, DVM

Born in Bryan, Texas, Dr. Dietz is the youngest of three children. Shortly after her birth, the Dietz family moved to Roanoke, Virginia where her parents purchased a small animal clinic. Dr. Dietz spent her childhood watching her mother, examine and treat cats and dogs. It was these childhood experiences and her mother that inspired Dr. Dietz to pursue a career in veterinary medicine. Learn More

Jackie Christakos, DVM


Dr. Christakos grew up in southern Illinois where she took riding lessons as a young girl. She became involved in eventing in high school, competing to preliminary level with her off-the track thoroughbred and helping manage a performance horse boarding facility before relocating to Colorado in 2004 to begin her undergraduate education.

Dr. Christakos received her Bachelor of Science degree and Doctor of Veterinary Medicine degree from Colorado State University in 2008 and 2012 respectively. She then completed her internship at Littleton Equine Medical Center in 2012-2013, rotating through surgery, emergency and field services.Learn More

Sara Senn, DVM

Sara Senn, DVM is joining us from Colorado State University in Fort Collins, CO.  Dr. Senn is a Colorado native and attended CSU both for her undergraduate degree, her masters in science degree and her graduate degree. Dr. Senn grew up riding and showing Quarter Horses. Dr. Senn enjoys gardening and playing sports such as volleyball and softball.

Jairo Paucart, MV

A native of Bogota, Colombia, Dr. Paucart moved to the United States to build his knowledge in equine veterinary medicine.  After completing several externship programs at several private practices, Dr. Paucart had the opportunity to visit Littleton Large Animal Clinic.  After finding an environment saturated with horses, passionate horse owners and veterinary professionals, he came on staff in 1999.

Dr. Paucart’s focuses at Littleton Equine Medical include; anesthesia, lameness, radiology, magnetic resonance imaging (MRI), and other imaging modalities. Learn More

Ethan Hefner, DVM

Ethan Hefner

Dr. Ethan Hefner was raised in Newton, North Carolina and spent the last 7 years in Raleigh, NC. He received his Bachelor’s of Science in Animal Science with a minor is Biotechnology. He then received his DVM from NCSU has a special interest in imaging and surgery.

Dr. Hefner has three horses (Ali, Casper and Hope) , two dogs (Menchy and Leo) and a goat named Taco.

He became involved with horses through 4-H where he began to show in western, huntseat and gaming events. He represented NC 4-H at Quarter Horse Congress and AQHYA World Show in horse judging and horsebowl. He started showing in the American Paint Horse Association in the all around events locally and attended the world show twice with his horse Casper. His favorite events are horsemanship, equitation, trail and western riding.

On his days off, Dr. Hefner enjoys playing piano, tennis, skiing, trail riding and hiking.

Katy Mayhew, DVM

Katy Mayhew

Dr. Katy Mayhew comes to us from Senoia, Georgia.

She received her B.S. of Agriculture in Animal Science from the University of Georgia and her DVM from the University of Georgia College of Veterinary Medicine. Her main interests are equine surgery and lameness, nutrition and reproduction.

Dr. Mayhew grew up riding and was very active in the local 4-H club through high school. In college, she was part of the Collegiate Horseman’s Association and a teaching assistant for two horsemanship courses. She was able to participate in several research projects dealing with gait quality. She also worked at the UGA Horse Farm prior to starting veterinary school.

Dr. Mayhew and her husband have a blue heeler mix named Daisy. When not at work, she enjoys trail riding, hiking, kayaking and distance running.

Nigel Miller, DVM

Nigel Miller

Dr. Nigel Miller was born and raised in Elizabeth, Co.

He received his B.S. of of Animal and Veterinary Science from the University of Wyoming, his M.S. of Animal Science from New Mexico State University, and his DVM from the Colorado State University.  His main interests are sports medicine, lameness, and nutrition.

Dr. Miller grew up training polo ponies and fox hunters with his mom.  Helping out with ranch work and competing in team roping.  He was a technician at Littleton Equine Medical Center during his undergrad years.  Dr. Miller completed projects researching venograms in non-laminitic horses as well as being co-author on a project to be presented at AAEP regarding post mortem examinations of aborted fetus’ in the field.  He was active throughout his CSU years and served as president of the CSU Student Chapter of the AAEP during his senior year.

Dr. Miller has a 22 year old gelding named “Headlight” that he enjoys riding while helping his mom out on their farm.  He also enjoys running, fishing, and hiking with his girlfriend.

Brooks Vardell, DVM

Brooks Vardell

Dr. Brooks Vardell is originally from Larchmont, New York. She received a BA from Washington and Lee University in English and Poverty and Human Capability Studies. She then received her DVM from the Ohio State University.

Dr. Vardell has two dogs, Butter and Tommy, and a Canadian Sport Horse named Holly.

Dr. Vardell grew up riding hunter/jumpers and competed in the Amateur Owner Jumpers with her mare Holly.

On her days off, you can find her reading, hiking with her dogs, riding and gardening.

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