Your Pet’s

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.

Kari and Pups

Kari Lemanski, DVM

Emergency Veterinarian

Dr. Lemanski was born and raised in western Pennsylvania and has always loved animals. To gain experience during her studies, she worked as a small animal veterinary assistant from 2013 throughout veterinary school, during summer and winter breaks.

She earned a Bachelor of Science degree in animal science at the University of Findlay in Ohio. After receiving her DVM from St. George’s University Veterinary School, she completed her clinical year at Ohio State University in 2020.

When not caring for animals at the hospital, she enjoys swimming, traveling, spending time with family, friends, and three dogs, Bella, Cooper, and Winston.


Kelly Schwanebeck, DVM

Emergency Veterinarian

A Florida native, Dr. Schwanebeck was raised in DeLand. She is a double Gator, obtaining her bachelor’s degree and subsequently her Doctor of Veterinary Medicine from the University of Florida.

Suffice it to say she is thrilled to be back in her hometown to serve the pets and their families in her community.

An outdoor enthusiast, she enjoys spending time with her family, friends, and fur babies. She also enjoys hiking, boating, exercising, and crafting.

Dr. Kuzimski

Lauren Kuzimski, DVM, MS

Emergency Veterinarian

Dr. Kuzimski received her MS in veterinary biomedical sciences and her DVM at Oklahoma State University. Following graduation in 2018, she spent the last few years working with a large percentage of exotics and in urgent care with dogs and cats.

She is excited to transition more into an emergency setting to help provide 24/7 care for all animals – from scales to furry friends. 

Outside of work, she spends time with her family, her own critters (her husband would call it a small zoo), and friends. She takes time to write, read, and find new adventures within her own nerdy hobbies (she’s excited to be within driving distance of Universal Islands of Adventure).
Dr. Arias

Sebastian Arias, DVM

Emergency Veterinarian

Dr. Sebastian Arias Laguillo was born and raised in Puerto Rico. His love for the field originated from taking care of farm animals with his grandfather. Dr. Arias graduated from St. George’s University in January of 2021, after completing his clinical year at the University of Minnesota. He has specific interests in ultrasonography and internal medicine. Outside of the clinic, he enjoys theme parks, tennis, trying various cuisines in the Orlando area, and spending time with his Airedale pup named Walt. 

Veterinary Technicians & Assistants

Client Services



Joshua Van Nieuwal

Hospital Manager

Joshua started as a veterinary assistant in 2008. While working at AEHV, he has learned valuable skills that he is applying to his career goal of becoming a Certified Veterinary Practice Manager (CVPM). The ‘go-to’ person at the hospital, Joshua is a natural problem solver and truly enjoys making sure the team has what they need to best serve all patients. He holds himself to high standards and cares deeply for the welfare of AEHV patients and team members.

Of course, Joshua’s home consists of a menagerie of pets along with his wife and son.

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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