Veterinary Staff


Meet the veterinarians and team of Riverside Veterinary Clinic! We’re pleased to provide exceptional vet care for your pets!

a cute cat looking up

Get to know our team!

We are solely dedicated to your pet’s care! We look forward to getting to know you and hope you’ll take the time to scroll down and get to know us.

Meet Our Veterinarians

Dr. Lagasse

Efronia Niki Lagasse


Dr. Lagasse is the owner of the Riverside Veterinary Clinic. She was born and raised here in Haverhill, MA. After graduating from Haverhill High School in 1977, she attended Michigan State University for two years and the University of Vermont for one year. She was a member of the second graduating class at Tufts School of Veterinary Medicine in 1984.

Upon graduation, she returned to her hometown of Haverhill to practice. In 1988, she and Dr. Crawford started the Riverside Veterinary Clinic. After thirty years, Dr. Lagasse has enjoyed all aspects of veterinary medicine and surgery. She especially enjoys client education and forming relationships with her clients and patients.

Dr. Lagasse resides in Newburyport with her husband, Michael, and their two sons, Robbie and Greg. When not at the clinic, she enjoys tending to her home and gardens, riding and caring for her two horses, playing with her three dogs and two cats, and watching over her chickens and quail. She also enjoys cooking, sewing, running, biking, skiing, snowmobiling, camping, and spending time with family members.

Dr. Owen
Elizabeth Owen


Dr. Owen has been at home in New England for over 20 years but grew up in Oklahoma, Texas, and Louisiana. Before attending Veterinary School, she worked at a medical research foundation and oil company where her jobs ranged from a Chemist to a New Products Manager.

She received her Doctorate of Veterinary Medicine from Oklahoma State University in 1991 and took her first job at a very mixed animal practice in Texas. There, she saw a wide variety of animals from cattle and horses (many mustangs) to zebras, lions, and her favorites… dogs and cats. After visiting and falling in love with New England, she worked at Stratham Veterinary Practice in New Hampshire for several years before joining Riverside Veterinary Clinic in 1996. She most enjoys the great client and patient relationships developed over the years and the challenge and diversity of general practice.

She lives in Hampton Falls with her husband, Mark, their Doberman, Shelby (who you may see around the clinic begging for cookies), their rescue dog, Jule, and their three cats, Peter, Kenny, and Jake. She enjoys traveling with her husband as he transports horses and sometimes rescue dogs around the country. In her leisure time, she likes gardening, hiking, and taking care of her horse, Willy.

John Ledoux
John Ledoux


Dr. John E. Ledoux was born and raised in Nashua, N.H. He attended Bishop Guertin High School and graduated in 1982. He then went to the University of Pennsylvania and received his Bachelor of Science in 1986 and his V.M.D. in 1990.

He took his first veterinary position at the Bethlehem Veterinary Medical Center, a ten-doctor practice in Bethlehem, Pennsylvania, where he received extensive private practice experience in surgery, medicine, emergency medicine, and ultrasonography. Desiring to move back to New England, he accepted a position at Andover Animal Hospital, where he worked as an associate and eventually the hospital medical director until 1999. In 1999, Dr. Ledoux moved to the Riverside Veterinary Clinic and started Mobile Ultrasound Service, servicing many of the surrounding clinics in the Merrimack Valley.

Outside of veterinary medicine, Dr. Ledoux’s current passions include reading, running, music, and spending time with his wife, Dr. Lori Gordon, and their two sons. They share their house with one dog, Davner Abigayle Gordon Ledoux.

John Defanti
John Defanti


​Dr. DeFanti is a 1991 graduate of Oklahoma State University and has been practicing in the Seacoast area for over 20 years. He has spent over half of this time in emergency medicine and has special interests in soft tissue surgery and dentistry. Outside work, he enjoys reading, listening to music, fine cuisine, and motorcycle riding. He lives with his wife, Michelle, a certified veterinary technician, their five cats, and many chickens.

Dr. Defanti has worked as a relief veterinarian at Riverside for many years. In 2015, he joined the staff as a full-time veterinarian.

Dr. Anderson
Kaitlin Anderson


Dr. Anderson was born and raised on the North Shore in Massachusetts. From age three, she knew she wanted to become a veterinarian. After graduating from Peabody High School in 2009, Kaitlin attended the University of Massachusetts Amherst, where she received her bachelor’s degree in animal science in 2013. She then went on to receive her DVM from The Ohio State University in 2017.

During her time in veterinary school, Kaitlin volunteered at the Ohio Wildlife Center and worked as a gymnastics coach at a local gym (Kaitlin was a gymnast for 11 years). After spending four years in Ohio, Kaitlin was ready to head back home. She took her first job at an emergency clinic in central Massachusetts. Desiring to move even closer to home, she then joined Riverside Veterinary Clinic in November 2017. She recently began volunteering at the spay/neuter clinic at the MSPCA.

Kaitlin lives with her boyfriend, Chuck, their dog Logan, and two cats, Paul and Cider (an RVC adoptee!). Outside of veterinary medicine, she enjoys traveling, reading, being outdoors, and spending time with family and friends. She is also a fan of all things Harry Potter.

Dr. Linda
Linda Thistle


​Dr. Linda Thistle grew up in Malden, MA. She earned a Bachelor of Science from the University of New Hampshire in 1988 and a Doctorate in Veterinary Medicine from the University of Tennessee in 1992. She completed a small animal medicine and surgical internship at Angell Memorial Animal Hospital in Boston, MA in 1993. She has been in private practice in the suburbs of Boston and the Merrimack Valley ever since.

Dr. Thistle is passionate about client education, preventative medicine, and rescue work. She resides in the Merrimack Valley with her husband, two sons, two dogs, and three cats.

Tabor DeGroot
Tabor DeGroot


Dr. Tabor DeGroot was born and raised in Charlotte, Vermont. He graduated from the University of Vermont in 2015 and moved out west for a year to work and ski in Jackson Hole, Wyoming. Shortly after returning to Vermont, Tabor rediscovered his interest in working with animals and enrolled in a pre-veterinary medicine post-baccalaureate program at UVM to earn his prerequisites for veterinary school. In the spring of 2023, he received his DVM from the Cummings School of Veterinary Medicine at Tufts University.

Outside of veterinary medicine, Tabor enjoys cooking, tennis, skiing, and getting outside with his family. He resides with his wife, son, two dogs, Akella & Rowan, a cat, Mr. Gatsby, and their duck, Plum Puddles, on the North Shore in Massachusetts.