Providing compassionate, professional veterinary care with advanced treatments, personalized attention, and a commitment to your pet’s health.
Internal Medicine
The U.C. Davis School of Veterinary Medicine is regarded as one of the top three veterinary schools in the world. As a graduate of this distinguished university Dr. Queen was honored as a resident by faculty for her clinical and teaching contributions in 2009. She also received the Small Animal Resident award from the senior students for her contributions to their education in clinical rotation in 2010. Her knowledge and expertise in Small Animal Internal Medicine are equaled only by her generosity to and compassion for all things big and small.
Education
Areas of Interest
Small animal internal medicine with particular emphasis in the areas of infectious disease, endocrinology, respiratory disease, and hepatic disease.
Research Publications
Honors & Awards
Professional Affiliations
Internal Medicine
Polina Vishkautsan, DVM, DACVIM, is a board-certified internal medicine specialist at MarQueen Veterinary Specialty Group – Upland, California location.
Dr. Polina obtained her DVM degree in 2001 from the Koret Veterinary School at the Hebrew University of Jerusalem. With a desire to continue her growth and practice some of the best veterinary medicine, she moved to New York to attend the prestigious Cornell Veterinary School of Medicine, where she passed her boards and qualifications to become a veterinarian in the United States.
After a rigorous internship at a 24-hour veterinary emergency and specialty clinic in Wisconsin, she completed a Small Animal Internal Medicine residency at the Angell Animal Medical Center in Boston.
Dr. Polina has since worked at several emergency and specialty hospitals in both Arizona and California. In 2014, she pursued a two-year Fellowship in Small Animal Infectious Diseases at the University of California, Davis, Veterinary Medical Teaching Hospital – rated as one of the best veterinary teaching hospitals in the world. During her fellowship, Dr. Vishkautsan subspecialized in treating both common and rare infectious diseases of dogs and cats and completed a research project on the use of anti-fungal drugs in cats.
Polina enjoys traveling the world in her spare time, pursuing exotic locals for bird photography with her partner Henry. Polina loves to hike, in particular, the Sonora Desert to explore the hidden gems of the beautiful state of Arizona.
Areas of Special Interest
Internal Medicine
Dr. Katarina Yi is one of three board-certified veterinary internal medicine specialists at MarQueen Veterinary Emergency and Specialty Group in Upland, California.
The Texas A&M Veterinary Internal Medicine residency is a highly sought-after and well-respected program recognized worldwide. MarQueen Veterinary Specialty Group is proud to add this impressive and diverse perspective that Dr. Yi brings to our Internal Medicine staff.
Katarina grew up in Dalton, Georgia, where she quickly gained a penchant for being a part of the best of something. This is because Dalton, Georgia, is renowned as the carpet capital of the world. Katarina would eventually embark on her veterinary path by attending the University of Georgia, where she would complete both her undergraduate and veterinary doctorate degrees with the highest distinction.
Dr. Katarina Yi was accepted into Texas A&M University, where she completed her residency in small animal internal medicine. Dr. Yi then efficiently and successfully satisfied the rigorous requirements to become board-certified in small animal internal medicine – Katarina Yi, DVM, DACVIM.
In addition to this impressive journey, Katarina worked as a flight attendant for a major airline to achieve her career goals in veterinary medicine. Naturally, she loves all things that involve travel – the world, the country, our national parks, and naps all along the way.
At the heart of MarQueen Veterinary Specialty Group, alongside her specialty colleagues, Dr. Erica Queen and Dr. Polina Vishkautsan, Dr. Katarina Yi brings a unique and noble perspective to internal medicine. Together, they combine the wisdom of experience and the fervor of growth, offering unparalleled care to both their patients and clients. Whether it be cutting-edge studies from the university or historical case experience in the private setting, both combined have the inevitable outcome of providing some of the best veterinary care in California.
Areas of Interest
While Dr. Yi enjoys all areas of internal medicine, she has a special interest in infectious diseases, gastrointestinal diseases, hepatobiliary diseases, and minimally invasive procedures.
Research/Publications
Oncology
MarQueen Veterinary Specialty Group includes oncology and is headed by our board-certified veterinary oncologist, William FitzPatrick DVM DACVIM (oncology). Dr. FitzPatrick has been a veterinary small animal veterinary oncologist in the Inland Empire for over a decade, serving Upland, Rancho Cucamonga, Claremont, La Verne, Chino Hills, and surrounding cities in and around San Bernardino and Los Angeles counties. Since childhood, William has had a love for dogs and cats, which eventually led him to work as a veterinary assistant at a veterinary practice during high school in Albuquerque, New Mexico.
Dr. FitzPatrick has an impressive educational background that begins with a Bachelor’s Degree of Science in both Biology and Spanish in his home state at the University of New Mexico. While Willam was at it, he obtained a Masters in Toxicology from UNM College of Pharmacy. This experience led him to study cancer and pharmacologic drug studies in both humans and animals. This collaborative oncology experience would set Dr. FitzPatrick on his journey into becoming a veterinarian and, ultimately, a veterinary oncologist for dogs and cats.
William left New Mexico for Fort Collins, CO, after being accepted into the prestigious Colorado State University School of Veterinary Medicine, where he obtained his degree in veterinary medicine. Dr. FitzPatrick then completed a one-year internship at the New Haven Central Veterinary Hospital in Connecticut. Dr. FitzPatrick first worked as a general practice DVM in routine care, emergency medicine, and surgery. He practiced for five years as a family veterinarian to establish a strong foundation before he embarked on his dream to become a veterinary oncologist.
After completing a three-year veterinary oncology residency program at Michigan State University, Dr. William FitzPatrick DVM passed his veterinary oncology board exam to become Dr. William FitzPatrick DVM DACVIM (oncology) and official dream achiever. Over the next three years, William practiced as a veterinary oncologist at veterinary specialty hospitals in Maryland and Massachusetts before moving his family to California, where he and his wife discovered they once both lived in the same city but had yet to meet. This mutual love of California would eventually bring Dr. FitzPatrick to MarQueen Veterinary Specialty and Emergency – Upland.
As mentioned, Dr. FitzPatrick has a Bachelor’s Degree in Spanish and is fluent in the Spanish language (spoken and written), which helps with our Spanish-speaking community. In addition, growing up in the western part of the United States, William has an affection for Mexico and South America. He has even traveled to Ecuador and the Galapagos Islands, where he experienced the diverse and unique species of plants and animals.
We would be remiss if we did not point out that Dr. FitzPatrick loves all sports, Football in particular, and is a fan of the Buffalo Bills, not because of his first name but because it is his mother’s hometown. Bill wants to point out that he cheers on both the Buffalo Bills and Baltimore Ravens when they play one another – a win-win! During these games, Dr. Fitzgerald is often joined by his dog, Maya, and cat, Lilly.
Dr. FitzPatrick is a member of the American College of Veterinary Internal Medicine and the American Veterinary Medical Association. He is also a member of the Veterinary Cancer Society and a past member of the Rocky Mountain Society of Toxicology. Since his residency program, he has been actively involved in teaching veterinary students and interns, clinical research, and various cancer trials.
MarQueen Veterinary Emergency and Specialty would like to share a few thoughts from past clients about our veterinary oncologist Dr. William FitzPatrick:
Surgery
Dr. Ibrahim started his veterinary career in Egypt, where he developed a love for all animals as a child. The more his career developed, Dr. Ibrahim realized his interest and ability to perform surgery at a high level of success. In 2018 he decided to pursue his passion and take the required steps to become a board-certified surgeon. After four years, Dr. Ibrahim successfully completed a surgical internship and his surgery residency. He is now eligible to sit for his board exams. Everyone at MarQueen Veterinary Specialty Group is committed to the best in veterinary care while in pursuit of the highest honors in veterinary medicine.
Mohammed loves to ride horses and his Ducati motorcycle to relax and enjoy his time.
Doctor Of Veterinary Medicine (DVM)
Surgical Training And Experience
Employment Experience
Research
State DVM Licensure
Professional Training And Continuing Education
Cardiology
MarQueen Veterinary Specialty Group is proud to partner with board-certified cardiologist April Durtschi, DVM DACVIM (cardiology). Dr. Durtschi is so passionate about her practice, her patients, and her clients that she has opened her schedule to MarQueen Pet Emergency and Specialty and provides veterinary cardiology consults, echocardiograms for dogs and cats (veterinary cardiac ultrasound), and treatment for cardiac disease in dogs and cats to Upland, Rancho Cucamonga, La Verne, Claremont, San Dimas, and all areas of the Inland Empire. In other words, Dr. Durtschi provides cardiology care for dogs and cats in the area so clients can avoid the stress their dogs and cats would otherwise need to endure with travel.
With some of California’s best veterinary emergency and specialty care, MarQueen Veterinary ER and Specialty Group have raised the bar by including dog and cat cardiologist Dr. Aprial Durtschi. The impressive road in her education and clinical practice cannot be overstated.
A lifetime of love for dogs and cats, April Durtschi obtained her veterinary medical degree from the prestigious Colorado State University. April then went to New York City and completed a one-year internship at the equally prestigious Animal Medical Center in Manhattan. Dr. April Durtschi then moved across the country to experience and practice 24-hour veterinary care, where MarQueen Pet Emergency founded their original hospital in Sacramento, California. It was there that April decided to pursue a path in veterinary cardiology. As a base, Dr. Durtschi completed a fellowship in comparative cardiovascular science at the University of Missouri. With this solid base, Dr. April Durtschi completed her cardiology residency at the University of Tennessee and passed the rigorous process to become a board-certified veterinary cardiologist.
April Durtschi, DVM DACVIM (cardiology), practiced cardiology for dogs and cats in New York, Connecticut, and Washinton before returning to California. Dr. Durtschi is especially interested in the medical management of chronic heart disease and works hard to set individual treatments for each dog and cat of every family. What is best and what makes sense is the ultimate goal of Dr. Durtschi at MarQueen Pet Emergency and Specialty.
Dr. April Durtschi can meet with clients and their dogs and cats by appointment at MarQueen Veterinary Specialty Group, located at 1582 N. Benson Ave, Upland, CA, and can be contacted at 909-303-1700.
Emergency
Dr. Strasser was raised near Seattle and attended the University of Washington where he received his bachelor’s degree in ancient military history. He went on to serve our country in the United States Marine Corps where he served four years in the infantry. Dr. Strasser returned to college in 2002 where he graduated from the UC Davis School of Veterinary Medicine.
With many years of diversified veterinary experience, Dr. Strasser practiced at several general practice clinics before he returned to his original passion – emergency and critical care medicine in 2018. He continued to build and grow his 24-hour vet experience and knowledge as he practiced veterinary medicine at veterinary hospitals across several states, which include the original MarQueen Pet Emergency and Specialty developed by Veterinary Internal Medicine Specialist, Dr. Erica Queen. Dr. Strasser is now a partner of MarQueen Veterinary Specialty Group in Upland and looks forward to helping both clients and their dogs and cats through the night. An experienced, caring, and humble veterinarian.
During his free time, he likes to be outside- hiking with his dog, riding bikes (dirt and mtn.), overlanding, and fly fishing.
Emergency
Dr. Jasmine Choi is an experienced emergency veterinarian and a native of Southern California. She achieved her undergraduate degree from the University of California, Irvine in Biological Sciences with the goal of being an ophthalmologist in human medicine. It was by chance that Jasmine volunteered as a kennel attendant and fell in love with the idea of helping dogs and cats.
Over the span of the next six years, Dr. Choi worked her way up as a veterinary technician assistant and grew her experience in the veterinary field before she decided to attend Western University College of Veterinary Medicine. After completion of veterinary school, Dr. Choi completed a small animal rotating internship at a veterinary specialty hospital in southern California. She continues to grow in all areas of veterinary medicine with surgery, pathology, and, of course, ophthalmology, as her main interests.
Once MarQueen Veterinary Specialty and Emergency opened a hospital in Upland, Dr. Choi was eager to be a part of this group of ER veterinarians, specialists, and experienced staff. MarQueen is fortunate to have an extremely dedicated and focused emergency doctor.
When not at the hospital, Jasmine stays active with running, cycling, surfing, or chasing her cat, Willie, for his nail trims. Otherwise, you can find her climbing at a local crag or planning her next big trip to find world-class bouldering somewhere around the world.
Emergency
Travis Vasconcellos, DVM, grew up in a residential area in O’ahu, Hawaii, in a large family of blue-collar workers. As a child, Travis would spend his summer days with his grandfather to help him care for all types of birds – lovebirds, parakeets, finches, ducks, and chickens. It was in these moments Travis’ grandfather saw something in Travis.
In 2013, Travis completed his undergraduate degree in Biological Sciences at the University of Hawaii. While Travis contemplated a career in the construction industry, he was accepted into Washington State University Veterinary School of Medicine and decided to continue the pursuit of Veterinary Medicine. In 2019, Travis graduated from veterinary school and became a veterinarian. Dr. Vasconcellos began his internship at a busy emergency practice in Southern California. In 2022, Dr. Vasconcellos joined the MarQueen Veterinary Specialty Group as a 24-hour emergency hospital veterinarian.
As children, our grandparents see our futures through love and wisdom, and the grandfather who told his nine-year-old grandson that the boy would become a “pet doctor” one day was sure right about Dr. Travis Vasconcellos.
When Travis is not saving lives, you can find him surfing, snowboarding, or hiking. He also loves to sip artisan beers and cheer at the television during Baltimore Ravens games while his cat Winter silently judges him.
Emergency
Stella Chu spent her childhood and teenage years in New Jersey. It was only appropriate that she earn her Bachelor of Science degree in animal science at Rutgers University. Dr. Stella Chu then obtained her Veterinary Medical Doctor degree at the University of Pennsylvania in 2015. Soon thereafter, Dr. Chu completed a one-year rotating internship in medicine and surgery at the University of Illinois in 2016, which was then followed by a specialty internship in internal medicine at Red Bank Veterinary Hospital, New Jersey, in 2017. After her two internships, Dr. Chu moved to Southern California and started her career working as an emergency veterinarian. She joined MarQueen Veterinary Specialty and Emergency Group as an emergency doctor in 2022 and has now joined full-time to grow her specialty skills while helping the emergency department.
After years of practicing medicine in the emergency room, Dr. Chu also completed her certification in veterinary acupuncture at Chi University in 2020 and is currently enrolled with the Canine Rehabilitation Institute working towards certification as a canine rehabilitation therapist.
Dr. Chu offers acupuncture and Chinese herbal medicine in her rehabilitation practice to facilitate optimal outcomes for post-operative patients and increases the quality of life for senior pets.
In her free time, Dr. Chu bakes all things warm and delicious, yells at football games on TV (go Giants!), travels, thrives on live music, and spends time with her husband, two pugs, and three cats.
Emergency
Monica Zamora grew up in and around Long Beach, California. She moved to the Inland Empire where she attended college at Cal Poly Pomona and received her BS degree in pre-veterinary studies to pursue her goal to be a veterinarian. Monica combined her love of Southern California with veterinary school and obtained her doctorate in veterinary medicine from Western University of Health Sciences. It was during the latter years of veterinary school that Dr. Zamora discovered a passion for 24-hour veterinary emergency medicine with a focused interest in traumatic soft tissue surgery, toxicology, endocrine emergencies, internal medicine, traumatic brain injuries, and pain management. With many years of experience working alongside specialists and surgeons, her knowledge and passion for helping dogs, cats, and clients have grown stronger. MarQueen 24 hour veterinary hospital is fortunate to have Dr. Zamora join our family of surgeons, internal medicine specialists, critical care technicians, and front staff in Upland, California. During her time off, Dr. Zamora loves to hit the leather off the ball in her co-ed softball league but retired a few years ago to root for her beloved Los Angeles Dodgers. In her downtime, she enjoys hiking, trivia nights, and dining out with her dog at pet-friendly restaurants.
Emergency
Beau Bedell DVM has many years of experience as an emergency veterinarian in both Northern and Southern California. He earned his undergraduate degree in Biological Sciences from Santa Clara University. In 2010, Dr. Bedell achieved his goal of becoming a veterinarian at one of the world’s top veterinary teaching hospitals, the UC Davis School of Veterinary Medicine.
Over the next several years, Dr. Bedell practiced veterinary medicine at several hospitals in and around the Bay Area. This diverse experience ultimately led him to recognize a shortage of after-hours support for emergency veterinarians in the community. For this reason, Dr. Bedell developed a strong interest in acute and emergency 24-hour veterinary medicine, where he could be available at night for patients who may need help.
Once MarQueen Veterinary Specialty and Emergency opened a hospital in Upland, Dr. Bedell was excited to join this crew of ER veterinarians, specialists, and experienced staff. MarQueen, along with the Upland, Rancho Cucamonga, and surrounding communities, is fortunate to have Dr. Beau Bedell available, as he is a strong overnight ER veterinarian.
Dr. Beau Bedell enjoys traveling with his wife and children when he is off from clinics. He enjoys football, golf, beer tasting, and, of course, dogs and cats of every kind.
Emergency
Dr. Tiffany Stehr is a graduate of the prestigious Colorado State University College of Veterinary Medicine and Biomedical Sciences and has pursued a career in emergency veterinary medicine. She grew up in Northern China, where her early experiences inspired a lifelong passion for helping animals live healthier, better lives.
Dr. Stehr completed a BA in Psychology and a BS in Biology, followed by CSU’s five-year program, earning both an MS in Toxicology and a DVM. She has experience in general practice and urgent care, high-volume private emergency medicine, and is now advancing into specialty emergency medicine. As a first-generation immigrant who independently financed her education through university and veterinary school, Dr. Stehr is deeply passionate about veterinary leadership and expanding opportunities for underrepresented and minority leaders in the profession, particularly in addressing opportunity gaps. She is eager to thrive in her career and focus on providing every patient the highest level of care possible. It is a tremendous opportunity to work alongside like-minded colleagues at the ER and specialty level to ensure every client and patient obtains the best medical and informative care possible.
Outside of work, Dr. Stehr stays busy with her young child, her playful Dachshund, Cinnamon, and the rest of her family. In her free time, she enjoys exploring new trails, trying new restaurants, and traveling with her loved ones.
The U.C. Davis School of Veterinary Medicine is regarded as one of the top three veterinary schools in the world. As a graduate of this distinguished university Dr. Queen was honored as a resident by faculty for her clinical and teaching contributions in 2009. She also received the Small Animal Resident award from the senior students for her contributions to their education in clinical rotation in 2010. Her knowledge and expertise in Small Animal Internal Medicine are equaled only by her generosity to and compassion for all things big and small.
Education
Areas of Interest
Small animal internal medicine with particular emphasis in the areas of infectious disease, endocrinology, respiratory disease, and hepatic disease.
Research Publications
Honors & Awards
Professional Affiliations
