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Your Pet’s Emergency

Emergency Veterinarians

Diane Johnson, DVM

Hospital Owner/Medical Director

Hospital Owner/
Medical Director

Dr. Johnson received her veterinary education at Ross University in 1994 and has practiced emergency medicine since that time. She has extensive training in all types of surgery, especially orthopedic, along with a special interest in cardiology and ultrasound.

Always looking to provide the most progressive care, Dr. Johnson is a life-long learner, constantly striving to add progressive technologies and acquire new techniques that will benefit her patients, from sophisticated diagnostic equipment to the latest in anesthesia, pain management, and pharmaceuticals. Dr. Johnson particularly enjoys training and mentoring veterinarians and technicians and witnessing their excitement as they master new skills that directly impact pets and their families.

In her free time, she enjoys spending time with family, her menagerie of pets including dogs, cats, horses, and birds, doing Bikram Yoga, and all kinds of water sports. Dr. Johnson’s latest hobby is exploring the country in her RV.

Cassandra Van Nieuwal, DVM, CVMA

Emergency Veterinarian/Co-Medical Director

Dr. Van Nieuwal followed the footsteps of her grandmother and aunt who have been involved with equine care and veterinary medicine for many years. By age 3, she was already tagging along caring for the animals and knew she wanted to become a veterinarian.

Dr. Van Nieuwal obtained her veterinary degree from Ross University in 2015 including her clinical year at Louisiana State University. While trained in all aspects of veterinary care, her strong interests are in exotic medicine and surgery, as well as endoscopy. In addition to her veterinary training at Ross University School of Veterinary Medicine and Louisiana State University, she also has prior work and teaching experience at Bowling Green State University Herpetarium. Wishing to further her ability to positively impact her patient’s healing process, Dr. Van Nieuwal became a Certified Veterinary Medical Acupuncturist in 2022. She is a mom to a plethora of pets including dogs, cats, a snake, and a turtle.

Having transplanted from Ohio to Florida to join AEHV, her free time includes enjoying the outdoors year-round, running with her dogs, horseback riding, snowboarding, paddle boarding, jet skiing, and spending time with family and friends.

Alyssa Carver, DVM, MS, CCRP

Emergency and Rehabilitation Veterinarian

After completing her veterinary degree at St. Georges University in Grenada, Dr. Carver took a position in western Pennsylvania close to where she grew up. With a little coaxing from a classmate, and the promise of year-round sunshine (plus a few hurricanes), the decision to take the plunge and become a Floridian was not that difficult. In addition to working in the ER, Dr. Carver oversees our rehabilitation services and is a Certified Canine Rehabilitation Practitioner, Fear Free Certified, and USDA Accredited. Outside of work, she loves the outdoors, enjoys boating, hanging out with friends, fiancé, and working out. Her current family consists of two cats that she adopted from Grenada named Tuko and KeeKee.

Alexis Bogosian, DVM

Emergency Veterinarian

Dr. Bogosian, or “Dr. B”, grew up in a small town in Connecticut and knew at a very young age that she was meant to be a veterinarian. She completed undergraduate studies at the University of Connecticut before moving to the Midwest for veterinary school. She graduated from Iowa State University College of Veterinary Medicine in 2014 and first worked in Ohio as an equine practitioner. Tired of the cold winters, she moved to Florida in 2015 and spent several years in mixed and small animal practices prior to joining us.

Aside from emergency medicine, her interests include soft tissue surgery and acupuncture. Dr. B loves to travel and has been fortunate enough to perform veterinary work on wildlife preserves in South Africa, as well as help control the stray animal population in Ecuador and on the Galapagos Islands.

When not at work, Dr. B enjoys spending time with her fiancé and their two dogs (Jax & Harley) and four cats (Oliver, Roo, Zoe and MRSA – yes, she has a cat named after a bacteria!). She loves going to the beach, riding her bike on local trails, hiking in national and state parks, watching crime documentaries, and baking cupcakes.

Gemma Massett, DVM

Emergency Veterinarian

Dr. Gemma Massett grew up in the heart of Kansas. She obtained her undergraduate degree and Doctor of Veterinary Medicine degree in 2021 from Kansas State University. After completing her education, Dr. Massett decided to move to Florida to be closer to her fiancé and enjoy the warm weather.

Dr. Massett is the proud owner of two beloved horses, Abby and Eddie, who have been by her side for most of their lives. Both horses made the long journey from Kansas to Florida with her, and they continue to be an important part of her life. In her free time, Dr. Massett enjoys outdoor activities such as biking and hiking, as well as spending time with her family and fiancé. She also enjoys reading and soaking up the sun on the beautiful beaches of Florida.

Veterinary Technicians and Assistants

Client Services


Sunni Willis, CVT, CCFP

Human Resources Manager

Sunni took the plunge and relocated to Florida from Massachusetts a few years ago. She is a certified veterinary technician (CVT) and has over 25 years of experience in veterinary medicine and hospital management. 

Sunni has two grown children. Her daughter has followed in her footsteps and is a veterinary technician, and her son is a history teacher. She shares her home with her husband and two Chihuahuas named John Gotti and Violet. Now that she’s settled into life in the Sunshine State, Sunni can be found restaurant hopping via boat, or volunteering for animal rescue groups. She is passionate about finding every dog a forever home. She is also an avid football fan, always rooting for her hometown New England Patriots.

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