Meet our Team

At the Animal Hospital of Nashua, our compassionate staff is committed to building strong client relationships and making sure our patients feel right at home. We are a close-knit group who work as a team to make your experience as pleasant and worry-free as possible.

We are fortunate to have knowledgeable and dedicated staff available every hour of the day and night. We are constantly striving to provide the best possible care by holding continuing education seminars for our staff members.


Chief Medical Officer

Leo Bishop, DVM

Dr. Bishop was born and raised in the dairy lands of Michigan and received his veterinary training at the College of Veterinary Medicine located at Michigan State University. Dr. Bishop began his career 30 years ago in a small animal veterinary practice in Dover, New Hampshire while working with the then-president of the American Animal Hospital Association. Considered one of the premier small animal practices in southern New Hampshire, this hospital offered Dr. Bishop the opportunity to control a heavy caseload, including 24-hour on-call care for his patients.

After leaving the Dover, New Hampshire area, Dr. Bishop practiced exclusively in the field of veterinary emergency medicine in the state of Massachusetts. In 1985, he founded the Animal Hospital of Nashua, which allowed him to expand his veterinary services to include not only general practice coverage, but also to provide 24/7 around-the-clock care. As one of the first veterinary hospitals in the area to offer this service, patients always had doctors and nursing staff in the hospital to provide continuing care. The latest addition to the hospital is a specialty practice that provides advanced veterinary services such as surgery and internal medicine by board-certified specialists. Dr. Bishop’s practice has progressed into a community hospital with a diverse set of practice groups residing under one roof, allowing Animal Hospital of Nashua to offer all-inclusive care to its patients.

As chief medical director, Dr. Bishop spends his time ensuring that the hospital provides the most up-to-date medical and surgical care for its patients while also emphasizing the need for exemplary client care. He shares his home with his wife and two dogs Chip, a Springer Spaniel, and Champ, a Golden Retriever, and cat, Wally, the boss. Dr. Bishop and his wife also have four grown children whom they enjoy visiting.

Dr. Bishop is a member of the American Veterinary Medical Association (AVMA), the American Animal Hospital Association (AAHA), and the Veterinary Emergency and Critical Care Society (VECCS).




Angel Cassista, DVM

General Practitioner

Dr. Cassista graduated from Atlantic Veterinary College at the University of Prince Edward Island in 2008. Since graduation, Dr. Cassista has been actively practicing small animal medicine, with focus on preventive care, illness diagnosis, treatments, and elective surgical procedures.

She is a long time resident of New Hampshire. She graduated Summa Cum Laude from The University of New Hampshire, Durham with a BS in Pre-veterinary Animal Sciences. Prior to attending UNH, she studied at Simon’s Rock College of Bard University, where she began her higher education at the age of 15. She graduated with her Associate’s Degree at 17.

Dr. Cassista’s professional interests include canine and feline preventive care, with special interest in dermatology. She also has experience with pocket pets such as rats, gerbils, and other small mammals.

In her spare time, Dr. Cassista enjoys knitting, sewing, leather tooling, and horsemanship. She and her fiancé Brian also enjoy providing large-scale puppeteering entertainment at the annual children’s Halloween event in Chester, NH.

She and Brian have three very polite cats named Mulligan, Danu, and Nottacat. Dr. Cassista is also owned by Claus, the American Saddlebred horse who followed her home one day!


Hasan Syed, DVM

General Practitioner

Dr. Hasan Syed was born and raised in Massachusetts and is the son of a veterinarian. After completing his undergraduate education in Microbiology from the University of Massachusetts in 2009, he spent two years working as a veterinary technician.

Further pursuing his passion of animal health, he went on to acquire his DVM from Ross University School of Veterinary Medicine and spent his clinical year at the Texas A&M College of Veterinary Medicine.

After graduation, he joined his father’s veterinary practice in the Boston area before joining our team in May 2016. Dr. Syed’s special clinical interests involve small animal preventive medicine, dermatology and neurology.

He enjoys trying new cuisines and traveling, a passion he enjoys experiencing with his wife. He is an avid sportsman, loves to ski, play volleyball and basketball.


Kelly Hansen, DVM

General Practitioner

Dr. Kelly Hansen grew up in Massachusetts before her family moved to Wisconsin. Dr. Hansen completed two years of undergraduate studies at the University of Wisconsin prior to early acceptance into veterinary school. She received her Doctorate of Veterinary Medicine Degree from the University of Wisconsin, School of Veterinary Medicine in 2004. Following her graduation, Dr. Hansen completed a year-long internship in small animal medicine and surgery at VCA South Shore Animal Hospital in South Weymouth, Massachusetts. Dr. Hansen joined our team in August of 2005. Her areas of interests include preventative medicine, geriatric medicine, and dentistry. She finds veterinary medicine extremely rewarding and greatly values the human-animal bond.

Dr. Hansen currently resides in Southern New Hampshire and shares her home with her cat, Colby, and her dog, Madison. When not at work, Dr. Hansen is spending time outdoors. She enjoys gardening, hiking, kayaking, and going to the beach.

Dr. Hansen is a member of the American Veterinary Medical Association (AVMA) and the American Animal Hospital Association (AAHA).


Lyana Buckwold, DVM

General Practitioner

Dr. Lyana Buckwold received her undergraduate degree from the Davidson College in North Carolina. She obtained her Doctorate of Veterinary Medicine degree from Ohio State University in 2012. Dr. Buckwold has extensive experience in general practice. She joined our general practice team at the Animal Hospital of Nashua in October of 2014. Her special interests include oncology and ophthalmology.

Dr. Buckwold resides locally in Nashua, New Hampshire sharing her home with her cat, Penelope.

Dr. Buckwold is a member of the American Veterinary Medical Association (AVMA) and the American Animal Hospital Association (AAHA).


Kate Sawyer, DVM

General Practitioner

Dr. Kate Sawyer grew up in Western Massachusetts, where the animals residing at a neighboring hobby farm were the genesis of her career path. Dr. Kate Sawyer received her undergraduate degree from the University of Wisconsin-Madison. She obtained her Doctorate of Veterinary Medicine degree from Iowa State University. She joined the general practice team at the Animal Hospital of Nashua in July of 2014. Her special interests include internal medicine, emergency medicine, and general practice.

In Dr. Sawyer’s spare time, she enjoys hiking and traveling; most recently traveling to South Africa for a wildlife capture expedition.

Dr. Sawyer is a member of the American Veterinary Medical Association (AVMA) and the American Animal Hospital Association (AAHA).


Nursing and Support Staff


Diagnostic / Lab Technicians

Controlling the diagnostic flow within the hospital, this team is responsible for collecting diagnostic samples, staffing our in-house laboratory, interfacing with outside labs, and providing accurate and timely reporting of diagnostic test results to our doctors.

Surgery Technicians

Our Surgery Technicians are responsible for three surgical suites and provide support for our surgeons. Their primary and most important duty is caring for the patient, which consists of assisting in surgery and anesthetic monitoring. In addition to patient care, they control and maintain the surgical equipment and instrumentation.

 X-ray / Ultrasound Technicians

Our X-ray and ultrasound technicians play a crucial part in determining medical care by providing the highest quality imaging for our doctors.

Outpatient Nurses

Our Outpatient Nurses are the doctors’ “right-hand men”.  They assist the doctors in all aspects of office visits, including medical, surgical, dental, and clinical laboratory procedures. They are willing and able to answer numerous questions while allowing the doctors to concentrate on the complete care of the pet. An important role of an Outpatient Nurse is to act as an advocate for the client and the patient.

Supporting Staff

Our supporting staff creates an environment that allows us to run an efficient and effective hospital. By ensuring that equipment is available and supplies are on hand, we are ready to meet the needs of any patient.

Client Service Representatives

Our Client Service Representatives are an energetic and friendly group committed to providing exceptional client service. Whether you are walking in the door or calling on the phone, they are here to support your needs and to answer any questions you may have.

Client Service Representatives schedule your appointments, check you in, assist you in checking out, and track your files and history for you.  They can also help direct you to the appropriate doctor who will be the best match for you and your family pet.

Working with our companion hospital, the Animal Medical Center of New England (AMC), we provide advanced care by board-certified doctors in multiple specialties. Visit the AMC website to learn about our specialists and referral services.





Catherine Reese, DVM, DACVS

Board certified surgeon

Graduating from Cornell University in 1991, Dr. Reese attended Tufts University’s School of Veterinary Medicine and graduated in 1995 with her Doctorate of Veterinary Medicine.

Dr. Reese completed an internship at Angell Memorial Animal Hospital in Boston in 1996, and then completed a small animal surgical residency at Cornell University in 1999. After her residency, she returned to Angell as a staff surgeon for almost 12 years, where she was Director of the Surgery Residency Program and trained over 30 new surgeons. She was board certified as a specialist in Small Animal Surgery by the American College of Veterinary Surgeons in 2001.

Dr. Reese is a member of American Veterinary Medical Association (AVMA), the Massachusetts Veterinary Medical Association (MVMA), and the Veterinary Orthopedic Society.

Jennifer McClellan, DVM, DACVIM

Board certified Internal Medicine specialist

Dr. Jennifer McClellan is Board Certified in Veterinary Internal Medicine. After obtaining her veterinary degree, she completed a rigorous residency program in this field, and successfully passed the Board Examinations to become an internal medicine specialist.

Dr. McClellan limits her practice to veterinary advanced imaging, and performs abdominal ultrasound and echocardiograms. She consults on those cases that require her expertise in advanced imaging.