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. 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 six years before joining the Olney-Sandy Spring team three years ago. 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  (AVMA), the Greater Baltimore Veterinary Medical Association, and the Maryland Veterinary Medical Association.  In the last year, she took over as the new Alternate Delegate  for the state of Maryland to the AVMA. She attends twice yearly AVMA Legislative meetings around the country to discuss and create policy and programs on past and present issues affecting the veterinary industry at large. 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 history teacher at Sherwood High School, her spritely five year old daughter Arabella, her  one and half year old energetic son Bodhi, and her dog Apollo - a one-eyed chihuahua- as well as her two cats -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 Kirby
Client Care Supervisor

Desirée Kirby

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 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 dogs, Nori and Marlon, and when not at work or playing with her dogs She 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

Alyse has always had a love for helping animals throughout her childhood, bringing home strays or trying to help little critters. She grew up in Cecil County and moved to Montgomery County in 2010. She joined the OSSVH family in September 2012.  In her free time she likes to spend time outdoors with her family, draw, paint and read a good book curled up on the couch with her Bengal cat Mancha. Alyse plans to continue her college education in the medical field.

Kathy Bell
Client Care Specialist

Kathy Bell

Kathy joined the OVSSH team in October 2017. She is a Montgomery County native and has had a love for animals since she was a child. Kathy has a strong background in customer service and started working for pet store chain in 2008.  She then moved into the veterinary field in 2011 as a receptionist. She loves working with clients and their pets.  You’ll recognize Kathy by her compassion for pets and their people and her bright sense of humor.  Kathy resides in Germantown with her two cats and three rats.  In her spare time, she likes to cook, hike, cross stich, crochet, and watch TV.


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.

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 working in the veterinary field in 2003 and then decided to go to school for it.  Michelle graduated from Wilson College in Chambersburg, Pennsylvania in 2009 with a Bachelors of Science degree in Veterinary Medical Technology and became a Registered Veterinary Technician that same year.  Michelle joined the OSSVH family in 2010.  She has a special interest in anesthesia, surgery, dentistry, and radiology.  When not working, Michelle enjoys spending time with her family, playing with her pets, taking pictures, the beach, camping, hiking, kayaking, traveling, walking, and other outdoor activities. Michelle and her husband share their lives with their children, Owen and Alaina, and their pets, a ferret named Abbey, a cat named Woody, and Kirby the Golden Retriever.

Kimberly Putterman
Veterinary Assistant

Kimberly Putterman

Kim grew up in West Hartford, CT and attended the University of Maine.  She graduated with a Bachelor of Science in Animal Science and a minor in Equine Studies.  She has previously worked at and emergency animal hospital in Washington DC, as well as an animal neurology practice in Rockville MD.  Kim Joined OSSVH in December of 2016.  In her free time she enjoys running 5k, 10k and half marathons, and going on adventures with her boyfriend and dogs Chevy and Otis.

Stacie Purnell
Veterinary Assistant

Stacie  Purnell

Stacie joined the OSSVH team in 2002 as a veterinary assistant.  She worked in the kennel and as the kennel supervisor for a period of time.  Stacie really enjoys providing nursing care to our patients, and  always treats them as if they were her own.  Stacie has two cats of her own Luke and Miste as well as two grown sons named Keith and Jamal. 

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.

Alyssa Windstein
Veterinary Assistant

Alyssa Windstein

Alyssa joined the OSSVH team in June of 2017.  She graduated from the Certified Veterinary Assistant Program at Carroll Community College in 2014. She shares her home with two dogs and two cats.  Alyssa spends her free time exercising and going to concerts.

Bridget Bart
Veterinary Assistant

Bridget  Bart

Bridget has been working with animals since she turned 15 and has a deep rooted passion for them. She has groomed dogs for 10 years and worked in the veterinary world for 3 years. She currently owns 2 shih tzus, a kitten, and has a beautiful daughter.  She strongly believes that each patient should be cared for and treated as if it were her own!

Jannell Johnson
Technician Assistant

Jannell Johnson


Katherine Lepter
Kennel Supervisor

Katherine  Lepter

Katie was born and raised on the eastern shore of Maryland. She  joined Olney-Sandy Spring Veterinary Hospital in the fall of 2016. Katie has always had a passion for caring for animals.  She is very quiet and calm and has a natural ability to connect with our boarding patients.    In her free time, she likes to play sports, hike, cook, travel and spend time with family and friends.

Rebecca Hasselberg
Kennel Assistant

Rebecca Hasselberg

Becca grew up in Charlotte, North Carolina.  She lived in Virginia before moving to Washington, D.C. with her family when the Navy transferred her husband to D.C.  Becca joined the OSSVH family in November 2017.  Prior to joining OSSVH, Becca worked at another veterinary facility and a boarding facility.  In her spare time, she enjoys spending time with her husband and two daughters.  Becca loves all animals, her favorite being the gorilla, but shares her home with two dogs, Cheyenne and Sam.


Christina Leon

Christina  Leon

Christina Joined OSSVH in May of 2018.  She has been grooming dogs and cats since 2005 and working with dogs since she was 12 years old. Christina grew up in Wheaton around many different dog breeds including Boston terriers, poodles, German shepherds, and Doberman pinschers. She believes in a gentle approach, that patience and love are key elements to grooming, and is committed to making your pet's experience comfortable, stress free, and safe. Christina lives in Gaithersburg with her family and when she isn't grooming pets, she enjoys going to the gym, listening to music, dancing, enjoying the outdoors and spending time with family.