Veterinarians and Staff


Dr. Karen Hoffmann

 Karen  Hoffmann

Prior to beginning her veterinary career, Dr. Karen S. Hoffmann received her MS from the University of Connecticut in biochemistry. She obtained her veterinary degree from the University of Minnesota in 1991. In veterinary school, Dr. Hoffmann focused on equine medicine, which she practiced for the first several years after graduation. Over the next few years, Dr. Hoffmann worked in several small practices throughout Maryland, transitioning to mixed practice and later exclusively small animal medicine.

Dr. Hoffmann joined Olney-Sandy Spring in the spring of 2000 and is OSSVH’s medical director. She has special interests in dentistry and behavior and takes a holistic approach to the wellness of all her patients. Certified to perform PennHIP studies, Dr. Hoffmann received formal training in the PennHIP Method of canine orthopedic evaluation from the University of Pennsylvania. She regularly attends local and national continuing education meetings.

In addition to her responsibilities at OSSVH, Dr. Hoffmann is an active member of the American Veterinary Dental Society, the American Association of Feline Practitioners, the American Holistic Veterinary Medical Association, and the American Veterinary Society of Animal Behavior, as well as the Maryland and American Veterinary Associations. As medical director and majority owner of the OSSVH practice, Dr. Hoffmann is also a member of a national veterinary study group that addresses business and management development.

Dr. Hoffmann is married to a professor of physics at the University of Maryland and the couple has three children. She spends her spare time running her farm, gardening, and breeding and obedience training her champion miniature schnauzers. She enjoys hiking, biking, and other outdoor activities.

Dr. Joellen Gregory

Joellen  Gregory

Dr. Joellen Gregory is a 2005 graduate from the University of Minnesota College of Veterinary Medicine. During school, she was a two-time AKC veterinary scholarship recipient, thanks to her involvement with the dog fancy. She has shown otterhounds in conformation, obedience, agility, and tracking since the late 1990s. Dr. Gregory has a special interest in reproduction, genetics, and canine sports medicine. She is currently studying to become a Diplomate for the American College of Theriogenologists. She is a member of the American Veterinary Medical Association and the Society for Theriogenology. In her free time, Dr. Gregory enjoys training and showing her dogs. When the dogs need a break, she enjoys traveling and music.

Dr. Kathleen Phillips

Kathleen  Phillips

Dr. Kathleen Phillips is a native of Montgomery County, having grown up in Rockville. She attended the University of Delaware for her undergraduate degree in biological sciences, and then obtained her veterinary degree in 2001 at Kansas State University. She completed a one year internship in small animal medicine and surgery at Friendship Hospital for Animals in Washington, DC, then spent a year in general practice before joining Dogs and Cats Veterinary Referral in Bowie, MD to practice emergency medicine. Dr. Phillips worked there for 6 1/2 years. She was in charge of the emergency service, managed the intern program, and worked very closely with the internists managing internal medicine and oncology cases. She worked at Peachtree Veterinary Clinic in the Poolesville area for 1 1/2 years until finally finding her home at Olney-Sandy Spring Vet Hospital. While Dr. Phillips is knowledgeable in all areas of veterinary medicine, she particularly enjoys internal medicine and oncology.

Dr. Phillips and her husband, Kyer, live in Silver Spring with their two Boston Terriers, Wrigley and Archie.  In June of 2013 they were overjoyed to adopt their newborn daughter Kaylen. Dr. Phillips is an avid Capitals and Redskins fan, and enjoys gardening, hiking, and most other outdoor activities.

Dr. Cheryl Stiehl

Cheryl  Stiehl

Dr. Cheryl Stiehl is a native of West Deptford, New Jersey but comes to Olney-Sandy Springs by way of Athens, GA. She completed her undergraduate degree in Avian Biology and Biological Sciences from the University of Georgia in 2008. Prior to attending veterinary school, Dr. Stiehl was a registered veterinary technician for many years both in private practice and at the University of Georgia College of Veterinary Medicine where she worked in the small animal intensive care unit.

Dr. Stiehl also completed her veterinary degree at the University of Georgia where she concentrated her studies in companion animal (canine, feline, and equine) medicine and surgery. She completed her acupuncture certification in Mixed Animal Acupuncture at the Chi Institute in 2011 during her third year of veterinary school. She has shown and bred Irish Setters since the late 1990's. Dr. Stiehl has a special interest in reproduction, complementary/holistic medicine, Traditional Chinese Veterinary Medicine, sports medicine, and surgery. Dr. Stiehl plans to pursue chiropractic certification and Chinese herbal medicine certification in the future. She is a member of the American Veterinary Medical Association, the Georgia Veterinary Medical Association, and the American Holistic Veterinary Medical Association.

Dr. Stiehl shares her home with her Irish Setters, a few spoiled rotten house cats, and Maverick, her wonderful Tennessee Walking Horse. Growing up 14 miles outside of Philadelphia, Dr. Stiehl is a die hard sports fan and attends as many Eagles, Phillies, and Flyers games as time allows. She is also an avid Bruce Springsteen fan and enjoys spending time with her dogs, horseback riding, reading, live music, and "the shore."

Dr. Jenny Krueger

Jenny  Krueger

Dr. Jenny Krueger, an Olney native, obtained her Bachelors in Animal Science from the University of Maryland, College Park prior to beginning her veterinary career. She graduated from the Virginia Maryland Regional College of Veterinary Medicine in 2008. She practiced general medicine in the Gaithersburg and Westminster areas for the last six years and enthusiastically has now joined the Olney-Sandy Spring team. She looks forward to sharing her passion and offering her expertise in surgical dentistry, soft tissue and orthopedic surgery, ultrasound imaging, and internal medicine.

Her background includes extensive experience repairing cruciate ligament (ACL) tears and luxating patellas as well as many specialty soft tissue surgical procedures. She has worked extensively with many rescue organizations including MCHS, FMCA, MAGDR and the D.C. Metro Transit Police dogs to provide affordable specialty surgeries as well as preventive care over the last several years. She received the Veterinarian of the Year Award from the Montgomery County Humane Society in 2010 for her efforts. She is a member of the American Veterinary Medical Association, the Greater Baltimore Veterinary Medical Association, and the newest Future Leader for the Maryland Veterinary Medical Association. She looks forward to eventually pursuing a residency program through the American Board of Veterinary Practitioners to become a specialist in canine and feline medicine and surgery.

Dr. Krueger resides in Olney, sharing her home with a vast menagerie that includes her husband, Josh, a teacher at Sherwood High School, her spritely two year old daughter Arabella, and her two dogs – Jaden, a great dane, and Apollo, a chihuahua- as well as her three cats- Ayla, Iza, and Durc. In her off time, she enjoys spending time with her human and animal family, reading, gardening, skiing, mountain and road biking, and any activity that gets her outdoors.


Denise Sharp
Practice Manager

Denise Sharp

Denise has worked in the veterinary field since she was old enough to get her first work permit. Throughout her career, she has worked in almost every capacity of veterinary hospital practice. She joined Olney-Sandy Spring Veterinary Hospital as veterinary technician and later took over the management aspects of the facility, freeing the veterinarians to focus on patient care. Denise earned her bachelor’s in biological sciences from UMBC in 1992. In addition to her responsibilities at OSSVH, Denise serves as a training officer for NVRT (National Veterinary Response Team), a federal disaster relief team for animals. She was deployed to assist the veterinary community in Mississippi following Hurricane Katrina. She is a member of the Maryland State Animal Response Team (MD SART) and the Anne Arundel County Animal Response team. She enjoys competing in flyball as a member of Blue Ridge Blast Flyball Team with her Keeshonden, Casanova and Lego, currently the number 1 and 3 Keeshonds, respectively in the North American Flyball Association. She also shares her home with a Katrina rescue, Grady, believed to be a Chihuahua/Jack Russell Terrier.

Client Care Specialist

Desirée Simmons
Client Care Supervisor

Desirée Simmons

Desirée joined the Olney-Sandy Spring Veterinary Hospital team in the fall of 2010. She is a native of Northeast Ohio and came to Maryland to pursue her Bachelor of Science degree at the University of Maryland, College Park.  She completed her undergraduate degree in Environmental Science & Policy, specializing in wildlife ecology and management in 2010. Prior to joining OSSVH, Desirée worked for the Army at their Veterinary Treatment Facility in Whidbey Island, Washington and a private practice in Virginia.

Desirée lives in Germantown, Maryland with her husband, Mike, an animal keeper at the National Zoo, their Otterhound, Sprocket, and cat, Scully – as well as a variety of reptiles including snakes & lizards. In her free time, she enjoys hiking with Sprocket & Mike, photography, traveling, cooking, and reading.


Liz Alexander
Client Care Specialist

Liz  Alexander

Liz grew up in Ashton, MD and her parents have been patients of Dr. Roskin since 1980. She attended Howard community college and has worked in the kennel since June 2001. Liz has two golden retrievers and when not at work or playing with her boys, Liz enjoys working out and spending time with family and friends at her vacation home in deep creek lake.

Alyse Sanchez
Client Care Specialist

Alyse Sanchez


Mandy Hendl
Technician Supervisor / Registered Veterinary Technician

Mandy  Hendl

Mandy Hendl, RVT is a Maryland native and earned her Bachelors degree from Hood College in 2005, majoring in biology. She became a registered technician in 2006 and has worked in both Pennsylvania and Maryland as a technician since 2002. Mandy joined our practice in January 2016. She has 3 cats (Osker, Styxx, & Willow) and a dog named Toby. In her free time, she enjoys spending time with her family, Celtic music, and reading.

Cheri Rice
Evening Technician Supervisor / Registered Veterinary Technician

Cheri  Rice

Cheri graduated from North Dakota State University in 1995, having received a bachelors of science in veterinary technology. She has worked in many veterinary hospitals across the country including two emergency practices and a cats only practice. She recently moved from Minneapolis, Minnesota, and is finding the winters in Maryland to be much milder than Minnesota winters! Working with cats, even the cranky ones, is what suits her the most. She recently lost her true feline companion of 19 years (the cat who taught her to handle and appreciate cranky cats) and it took her a while to find a new friend. Pixie is currently the only cat being spoiled at Cheri's house. When not at work, Cheri can be found at the movies, gaming (either on a computer or board games), or knitting.

Michelle Little
Registered Veterinary Technician

Michelle  Little

Ever since Michelle can remember, she has always had a passion for caring for animals and always knew this would be her life-long career. She began in the veterinary field in 2003 as a kennel technician and then in 2006, after some college experience, she changed positions to a veterinary technician. Michelle graduated from Wilson College in PA in 2009 with a Bachelors of Science degree in Veterinary Medical Technology and became a Registered Veterinary Technician that same year after passing her boards. Michelle joined the OSSVH staff in the fall of 2010. When not working or playing with her own animals, Michelle enjoys scrap booking, taking pictures, camping, hiking, kayaking, traveling, walking, and other outdoor activities. Michelle and her husband share their lives with a ferret named Abbey, a cat named Woody, and Kirby the Golden Retriever.

Alaila Cabrera
Veterinary Assistant

Alaila Cabrera

~~Alaila currently resides in Waldorf Md, where she recently purchased her first home. Originally from Hampton, Va., she migrated to the DMV area to pursue a Bachelors of animal science @ UMD, College Park with plans to attend Veterinary school. Realizing shes more of a behind the scenes of girl she has settled in to tech life and loving it. ​

In addition too working at OSSVH,  ​Alaila has also been a vet tech at the Montgomery County Animal shelter in Gaithersburg, Md. for the past three years. All but 1 of her 5, four legged kids have come from the shelter The is Mosiac (Mo) the 2 year old Black Mouth Cur, Monkey the 2 yr old Pt Bull , Mr Big a 2 lb toy Pomerian, and Chunky a 3 years old Mastiff mix. Last but certainly not least is Poptart, a 14 year old DMH that is the man of the house.  ​Although she doesn't have much free time, when she does she enjoys spending time with family, and cooking.

Stacie Purnell
Veterinary Assistant

Stacie  Purnell

My name is Stacie Purnell, I have been employed at Olney-Sandy Spring Veterinary Hospital for 12 years. I really enjoy patient care and promise that while your pets are here at the clinic, I will love and care for them as if they were my own. I am the owner of Stacie's Tasty Treats For Dogs which specializes in homemade natural dog treats. I have two wonderful and loving sons name Keith, 23 year old and Jamal, 21 year old.

Carolina Herrera
Veterinary Assistant

Carolina  Herrera

Carolina Herrera, is born and raised in Silver Spring, MD. She  joined Olney-Sandy Spring Veterinary Hospital in the Spring of 2016. She always knew growing up that she loved animals. She is the proud owner of two dogs Otto (Yorkie-poo) and Benji (Bichon). She also has a beta fish named Bubbles. In her spare time, she enjoys cooking and trying out new recipes. She will be going to school to become a veterinary technician. It is her ultimate goal to work with wildlife in their natural habits, especially elephants.

Chris Wojtaszek
Veterinary Assistant

Chris  Wojtaszek

Chris has been working in the veterinary field since 2002, ​ initially satisfying his love for animals by working as a Radiology Technician at a Specialty Hospital, he also went on to work with primates and misc. animals with the Division on Veterinary Resources at the National Institutes of Health.Also spending a year working with the Research Team at Georgetown University.In 2013 Chris was contracted out to help with the start up of the new Montgomery County Animal Services and Adoption Center. In the last 2 years since he is so ​ passionate about all aspects of veterinary medicine, he worked at an Orthopedic Specialty Hospital as a recovery technician. He is especially challenged by being motivated to constantly learn and improve. During his spare time Chris and his wife Ana, love staying at bed and breakfasts and spending their weekends exploring. They enjoy visiting historical sites. When they are not traveling, they enjoy their four-legged children -- two Chihuahuas, a miniature Yorkie and a Bichon. Other interests include photography and camping and festivals.

Sarah Strasser
Veterinary Assistant

Sarah  Strasser

Sarah grew up in rural upstate New York where she had black labs, german shepherds, and cats. She moved to Montgomery County as a freshman in high school. Sarah is currently enrolled at Montgomery College. Her current pets include a cat named Artemis and a Boston Terrier called Dax.


Christine Clem

Christine  Clem

Christine has groomed dogs for almost two decades and continues to have a passion for her work. She joined OSSVH in March 2003 and enjoys the challenge of working with a variety of breeds and getting to know each animal’s unique temperament. Christine’s goal it to maintain breed standards while providing practical care that meets the needs of pets and owners. She takes care to make the grooming process a pleasurable experience for the pets and she educates clients on how to maintain their pets between groomings. In her free time, Christine shows her toy Manchester terriers in the conformation ring. She and her family love camping, jet skiing, riding motorcycles, and spending as much time in the outdoors as possible.