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  • 961 Cayots Corner Rd
  • Chesapeake City, MD 21915 United States
  • P: (410) 885-3202
  • P: (877) 658-3328
  • F: (410) 885-3206
  • info@SelectBreeders.com

SBS Staff

SBS Main Facility - Maryland


Paul Loomis MS, Founder and CEO of Select Breeders Services Inc.

Paul LoomisPaul established Select Breeders Services in 1987 and developed the company to become the largest provider of equine semen preservation services in the world. As CEO of the company, Paul directs the international network of affiliated laboratories. During 1987-1992, Paul was also Director of Biological Research at Hamilton Thorn Research Associates. Hamilton Thorn is best known in the horse industry as developers of the Equitainer system for cooled transported semen and instrumentation for computerized sperm motility analysis. Prior to SBS and Hamilton Thorn, Paul was VP/General Manager of Green Hills Farm, Inc in Aiken, SC a large sport horse breeding facility. Here Paul developed (what was then) the largest commercial frozen semen breeding program for horses in the U.S.

Paul is a recognized expert in the field of semen preservation. He is a graduate of Colorado State University with a M.S. in Physiology (Equine Reproduction). He is the author of numerous scientific journal articles and regularly lectures worldwide in the areas of equine reproduction and semen preservation.

Dr. David B. Scofield DVM, MS, DACT, President and Medical Director

David Scofield 2015Dr. Scofield grew up in Delaware and on the eastern shore of Maryland. After college in North Carolina, he received his DVM from Oklahoma State University in 2009. Following graduation, Dr. Scofield completed an internship at Weatherford Equine Medical Center in Weatherford, Texas and later joined Colorado State University’s Equine Reproduction Laboratory for a residency in Equine Reproduction. His research focused on anti-microbial agents for bacterial and fungal infections in mares. His day-to-day activities included managing reproductively challenged mares and stallions, embryo transfer, foaling mares, high-risk pregnancies, and neonatal foals.

Jonathan Clark, Vice President and Chief Operating Officer 

Jonathan ClarkJonathan graduated from the University of Delaware in 1999 with a Bachelor of Science Degree in Animal Sciences.  While obtaining his degree, he started working for SBS in 1994 by assisting Paul with routine lab cleaning.  He began gaining more responsibility in the company by becoming a freeze technician, helping to pioneer the mobile lab use throughout the East Coast, and becoming the leader of the import/export department in Maryland.  Now, he dutifully holds the roles of Vice President and Chief Operating Officer for Select Breeders Services.  Though he still enjoys occasionally spending time in the mobile lab, Jonathan oversees and assists the managers of SBS Veterinary Services, Select Breeders Services Headquarters in Maryland and Select Breeders Southwest in Texas with their daily operations.  When not in the office, he spends his time focusing on the warmblood breeding operation he and his partner created. 

Kim Rennewanz, Director of Operations

Kim 200xKim joined the SBS team in February of 2023 as Director of Operations.  After working within many facets of the veterinary field for over 20 years, she brings diversity, an extensive background and experience to her role.  Kim spent a large part of her career as a small animal veterinary technician specializing in Emergency/Critical Care and Internal Medicine.  While working with a large and well known veterinary pharmaceutical company she fielded calls from veterinary professionals all over the United States.  Her work included drafting reports regarding efficacy and safety for products that are still on the market today; these reports were later submitted to the USDA and FDA for review.  Over the last 7 years Kim has worked as a Practice Manager at two very large facilities in Pennsylvania.  Her love of horses began as a child, so she is very excited to be refocusing her career on equine services and all the great work being done at SBS.  When not in the office, Kim enjoys spending time with her husband and daughters and training with her pit bull, Lilly, as they work towards certification as a therapy team. 

Affiliate Program

Erin Bishop MS, SBS Affiliated Laboratories Network Director

Erin Bishop MSErin has been with SBS since 2000.  She graduated from Kansas State University in 1997 with her Bachelor of Science Degree in Animal Sciences.  After graduation, she attended Colorado State University as a graduate student under the guidance of Dr. Ed Squires.  After obtaining her Masters of Science Degree in Reproductive Physiology, Erin began working at Select Breeders Southwest (SBSW) as a frozen semen technician.  She worked her way through the ranks of the company and became General Manager of SBSW in 2010.  She performed those duties until her family moved out of state in 2013.  She remained with SBS for the next 10 years doing various tasks with the website, email marketing and assisting with the SBS Affiliate Program.  Erin took on the role of SBS Affiliated Laboratories Network Director in January 2024.   

Associate Veterinarians

Dr. Elena Martinez de Andino VMD, Diplomate ACT, SBS Veterinarian

Elena Martinez de Andino, VMDDr. Martinez de Andino is a board certified Theriogenologist offering a wealth of knowledge to our equine and canine clients with her experience in assisted reproductive techniques including transvaginal oocyte aspiration and embryo transfer as well as breeding management for "problem" mares and subfertile stallions.  She graduated from Dartmouth College with a Bachelor of Arts degree in Hispanic Studies and went on to receive her degree in veterinary medicine from the University of Pennsylvania in 2016.  During her studies in veterinary school, she was a summer research fellow through the Havemeyer Behavior Lab in which she evaluated operant learning performance in foals using target training.  After graduating from veterinary school, she completed her rotating equine internship at Mid-Atlantic Equine Medical Center from 2016-2017.  She then completed her residency in equine theriogenology at Texas A&M College of Veterinary Medicine where she conducted research on intrafollicular oocyte transfer in conjunction with the Equine Embryo Laboratory.


Larissa Davidson, CPAController/Bookkeeper

LarissaLarissa received her Bachelor of Science in Accounting from Towson University in the Fall of 2012.  She then went on to pass the Certified Public Account exam in 2015.  As the Controller/Bookkeeper of SBS and SBS Veterinary Services, she assists our management teams with the planning, directing and coordinating of all accounting functions.  Prior to Larissa joining our team, she worked at a public accounting firm where she was a senior auditor.  When she's not in the office, she enjoys spending time outdoors, reading, quilting and keeping up with her daughters.

Allie Haymans, Accountant

Allie HaymansAllie earned an associate degree from the College of Southern Maryland in LaPlata while playing on a nationally recognized volleyball team which finished 5th in the nation.  She earned a scholarship to Division I, University of Louisiana, Monroe and graduated with a Bachelor of Arts in 1990, focusing on Management/Marketing.  She continued her studies at ULM and graduated in 1993 with a Master of Business Administration with a focus on Management/Marketing, all while coaching at the Division I level.  She returned to Maryland and married her college sweetheart.  Now that their three sons are grown, her spare time mostly consists of following her husband and Labrador Retrievers, Ranger, Dany and Rebel around the Retriever Field Trial Circuit, with her trusty Nikon in-hand.    

Rebecca Balon, Accounting Assistant

Rebecca 200x

Rebecca joined the SBS team in October of 2023.  Outside of work she enjoys spending time with her husband and three grown daughters.  During the warmer months, you will find her at the beach or boating on the river while enjoying a glass of wine.

Client Services

Cassie Bristow, Office Manager

CassieCassie has been a part of the SBS Administrative team since 2022.  She assumed the role of Office Manager earlier this year.  She grew up splitting her time between Kentucky and Maryland but settled back on the Eastern Shore in 2017 after marrying the love of her life, Brian.  She has 30 years of Customer Service, Finance and Office experience.  This coupled with her love of horses makes SBS her dream job!  In Cassie's free time, you can find her loving on her menagerie of animals, riding her horses, spending time with family or attending church.

Frozen Semen Shipping & Distribution

Caitlin WalshStorage and Distribution Manager

Caitlin WalshCaitlin received her Bachelor of Science in Animal Science and Equine Science from Penn State University.  As our Storage and Distribution Manager, she is in charge of preparing frozen semen shipments for domestic and international distribution, receiving and transferring incoming shipments and maintaining our inventory records as well as maintaining proper liquid nitrogen levels in our many frozen semen tanks.  She also assists our clients with their shipping and inventory questions.  When not in the lab, she enjoys painting and competing with her terriers in field trials.

Charlotte MacDonald, Frozen Semen Storage and Logistics Technician

Charlotte 200xCharlotte joined the SBS team in August 2023.  As the Frozen Semen Storage and Logistics Technician she assists the Storage and Distribution Manager in shipping, receiving and the monitoring of frozen specimens.  Outside of work she enjoys spending time at the beach with her husband and pit-mix Daisy as well as being a part of a local dirt track racing team's pit crew.


Holly Britz, Head Veterinary Technician

Holly BritzHolly received her Bachelor of Science in Animal Science, with a major in Equine Science, from Delaware Valley University.  As Head Veterinary Technician with SBS Veterinary Services, Holly fills the role as Dr. Scofield's right-hand lady.  She is responsible for daily treatments of the resident horses, ensuring the facility is well stocked, communicating with clients as needed and much more.  When she isn't working with the horses Holly likes to try out new recipes in the kitchen.

Kayla Williams, Laboratory Manager

Kayla WilliamsKayla received her Bachelor of Science in Veterinary and Biomedical Science, with a minor in Animal Science, from The Pennsylvania State University.  She joined the SBS team as a laboratory technician in August 2021.  Her role includes collecting semen and processing it for cooled/frozen shipments, assisting with extender production and ensuring the lab is clean and properly set up for each new day.  Kayla assumed the role of Laboratory Manager in April 2023.  Prior to coming to Maryland, she worked as a research assistant on projects with dairy cattle and ruminant nutrition and was an assistant barn manager at a farm in Pennsylvania.  When not in the lab, Kayla likes to snowboard, paint and enjoy time outdoors with her dog.

Ashley Steffan, Laboratory Technician / Veterinary Technician

Ashley SteffanAshley received her Bachelor of Science in Animal Science, with a minor in Equine Science, from Penn State University.  She fills dual roles at SBS.  During the fall and winter months she serves as a laboratory technician at our stallion facility performing stallion collections for the processing of frozen semen, produces and ships extenders, etc.  Then, during the spring and summer, months she has the opportunity to be outside with the horses while performing various tasks as a veterinary technician for the vets at SBS Veterinary Services.

Tatiana Lazzeri, Laboratory Technician / Veterinary Technician

Tatiana LazzeriTatiana joined the SBS Lab Team in October of 2022 after graduating from the University of Maryland with a Bachelor of Science in Animal Science in 2019.  Her responsibilities include collecting stallions, processing cooled/frozen semen, and all other duties in the lab including assisting the veterinarians with bloodwork and processing semen collections.  Tatiana has been around horses since the age of eight.  She spent most of her life living in Maryland until she moved to Kentucky in 2020.  There she worked at WinStar Far LLC, a racehorse breeding facility, for three years.  Her duties ranged from assisting in foaling, taking mares to the breeding shed and preparing yearlings for sale.  Tatiana also worked with the overnight foal watch team during the peak of foaling season, which produced over 100 foals. She also worked in a quarantine barn with sick foals providing nursing care.  After recovery, many of these foals went on to capture a significant price at the yearling sale.  Returning home to Maryland has allowed Tatiana to spend time with her family, which includes her 3 year old nephew.  When not in the lab, Tatiana spends time with her cat, Tito, who is the most dog-like cat that you will ever meet.  She also enjoys learning new things in the equine world, going out and enjoying a glass of wine while watching a show or reading a good book. 

Colleen Ellzey, Laboratory Technician

Colleen EllzyColleen graduated from the University of Kentucky in 2023 with a Bachelor of Science Degree in Equine Science & Management with a minor in Animal Science.  She grew up on a diversified farm in Southern Mississippi where she developed a passion for caring for animals, especially horses and cows.  While an undergraduate, she did an internship during the breeding season at the 6666 Ranch in Texas where she found a love for working with stallions.  After graduation, Colleen joined the SBS team in February 2024 as a laboratory technician where her roles include collecting semen, processing cooled and frozen semen, and the daily cleaning and stocking of the lab.  In her free time, she enjoys spending time with her Australian Shepherds and Quarter Horses.  

Sara Sheats, Laboratory Assistant

Sara began work as a Veterinary Technician at Chestertown Animal Hospital in 2016 and joined the SBS Lab Team in August of 2022. Her responsibilities include keeping the laboratory clean and fully stocked.  Sara attended the University of Delaware and graduated with a bachelor's degree in Pre-Veterinary Medicine with a minor in Equine Science.  In her free time, Sara enjoys reading, hunting and hiking.

Horse Care Team

Alexa Aguilar, Equine Facility and Horse Care Supervisor

Alexa AguilarAli graduated from Delaware Valley University with a Bachelor of Science in Equine Studies, with a focus in Business Management.  As Equine Facility and Horse Care Supervisor, she is responsible for overseeing the care of the horses, facilities, etc.  In her free time, Ali likes competing with her OTTBs and spending time outside.

Sergio Gomez, Stallion Manager

Sergio GomezAt the age of three, Sergio was introduced to horses by his grandfather who taught him everything he would ever need to know.  After high school, Sergio worked at Winbak Farm for over 3 years as the Yearling Manager and Stallion Handler.  Sergio went on to establish himself as a Stallion Manager with Northview Stallion Station, where he remained for 14 years.  Sergio has been a part of the team at SBS for the past two years and enjoys his role.  He is very grateful for the opportunities that all three facilities have provided him and prides himself on the contribution he has made in each of his roles.  Working with horses has been a wonderful experience for Sergio.  He credits his knowledge and experience as a Stallion Manager for providing a good reputation within the horse industry and hopes to continue his work for a long time. When Sergio is not in the barn, he enjoys riding and training horses.  

Carlos Espinoza, Team Member

Carlos Espinoza-Sanchez

Julianna Thawley, Barn Hand/Technician Assistant

Julianna ThawleyJulianna, is currently finishing her Business Degree from Southern New Hampshire University.  Her primary responsibility is to provide the daily care of the horses.  Jules, as she likes to be called, also has a photography business.  Many of her photos can be seen on the SBS website and the SBS Instagram profile.


Michael WootersFacilities Manager

Michael 200xMichael joined our team in 2023.  Growing up on a farm gave Michael a vast knowledge of animal care and a hard work ethic. Outside of SBS, he runs a lawn care business and loves to enjoy all the eastern shore has to offer with his fiancé and their dogs.