We’re one big family.
Get to know the team of people that will be there when your family needs us most. First up, our veterinarians!
I am often asked – “How can you do your job? It must be really sad to take care of cancer patients?” I absolutely agree that it is sad. But it is also so much more than sad – it is also challenging to determine the best treatment for an individual pet, it is rewarding to see patients win the battle and beat their cancer, and it is promising that early diagnosis and new treatments may improve our patients’ outcomes. Although it is sad and heartbreaking to hear the diagnosis of cancer in our pets, I see it as a personal challenge to ensure a good quality of life while patients are undergoing treatment. Dr. Ratterree and I founded CancerVets because of the need for experienced, board-certified oncologists in Naples and the surrounding area. We are committed to providing compassionate, comprehensive cancer care for pets in this community. Cancer bites, let’s fight back!
William Ratterree, DVM, DACVIM, DACVR
Board Certified Specialist in Medical and Radiation Oncology
Dr. William Ratterree is originally from South Carolina and pursued an Animal and Veterinary Science degree at Clemson University. He received his doctorate in veterinary medicine at the University of Georgia in May of 2008. He completed a small animal surgery and medicine internship at Louisiana State University, School of Veterinary Medicine in July of 2009.
Dr. Ratterree stayed on at the Louisiana State University, School of Veterinary Medicine to complete a medical oncology residency in July of 2011. He received his board certification by the American College of Veterinary Internal Medicine in May of 2012. A strong passion for treating small animal oncology patients with multimodality treatments led him to pursue a second residency in radiation oncology at Louisiana State University, School of Veterinary Medicine. He recently completed his radiation residency in July of 2013 and became boarded by the American College of Veterinary Radiology in September of 2013.
With the unique background of being boarded in both medical and radiation oncology, it allows him to formulate multimodality treatment plans specific for each patient keeping in mind quality of life and the human-animal bond. Dr. Ratterree has a special interest in combining newer radiation techniques (IMRT & SRS) for his patients in combination with chemotherapy and alternative techniques. Dr. Ratterree has headed the oncology, radioiodine departments at multiple veterinary hospitals in South Florida, serves as a radiation oncology consultant for multiple clinics nationwide, is adjunct oncology faculty at Louisiana State University, School of Veterinary Medicine and in addition holds the seat of Secretary for the Collier County Veterinary Society (CCVS).
Dr. William Ratterree and Dr. Carrie Kosarek, husband and wife, are the founders of Cancer Veterinary Centers. They saw a great need for a specialized veterinary oncology center on the west coast and in June 2016 moved here from the east coast of Florida and opened Cancer Veterinary Centers at the Naples location in the Emergency Pet Hospital. In April 2017 they opened the second location in Bonita Springs, which is a state-of-the-art cancer center to include radiation therapy.
When he is not tending to his local or distant patients, Dr. Ratterree is spending quality time with his family, his 2 cats, Luke and Leia and puppy Finn. During football season you will find him cheering on his favorite team, the Clemson Tigers! He also aspires to get his private pilot’s license.
- Bachelors of Science, Clemson University
- Doctor of Veterinary Medicine, University of Georgia
- Diplomate, American College of Veterinary Internal Medicine
Board Certified in Oncology
- Diplomate, American College of Veterinary Radiology
Board Certified in Radiation Oncology
Dr. Stephanie Byrne
Dr. Stephanie Byrne grew up in a military family and has called many places home. She has lived along the Pacific Coast, Nevada, Missouri, Virginia, and Florida. Dr. Byrne completed her undergraduate degree at the University of California, Berkeley.
Then, she started her medical oncology residency at the Royal Veterinary College in the United Kingdom in 2014, which she completed in July 2017. During her residency, she also completed a Masters of Veterinary Medicine degree.
Dr. Byrne knew from an early age that veterinary medicine was a passion for her, based on her experiences in shadowing her family veterinarian at his clinic. Once in veterinary school, the choice to pursue an Oncology specialty was an easy decision, as this opened a way for her to combine her love of clinical pathology with the reward of interacting with and treating patients. Her special interests lie in hematopoietic and histolytic malignancies, clinical trials work, and personalized therapies for patients that emphasize the quality of life.
Dr. Byrne is thrilled to be back home in the United States and is excited to explore Florida’s gulf coast. When she’s not practicing medicine, you can usually find her hitting the trails or agility floor with her Flat-Coated Retriever, Jitterbug. She is an avid runner and reader, enjoys outdoor sports, and is a country gal at heart.
- Bachelors of Science, University of California – Berkley
- Masters of Veterinary Medicine, Royal Veterinary College
- Doctor of Veterinary Medicine, Royal Veterinary College
Dr. Carrie Kosarek
Dr. Kosarek was born in Illinois but grew up in St. Petersburg, Florida and she attended The University of Florida for both her undergraduate and veterinary degrees. She graduated with her Doctorate of Veterinary Medicine in 1999 and continued her training at Florida Veterinary Specialists in Tampa, Florida as a rotating small animal medicine and surgery intern.
She then completed a one-year oncology internship prior to starting her medical oncology residency at The Ohio State University in 2001. Dr. Kosarek completed her residency and Masters of Science degree in 2004 and she became a Diplomate in the American College of Veterinary Medicine at that time.
After working in Tampa, Florida as the staff oncologist for 2 years, Dr. Kosarek was a clinical assistant professor at the University of Georgia from 2006 – 2008. Dr. Kosarek moved back to Florida in 2009, where she held the position of an associate oncologist and intern director at Animal Cancer Care Clinic until March of 2016.
Dr. Carrie Kosarek and Dr. William Ratterree, husband and wife, are the founders of Cancer Veterinary Centers. They saw a great need for a specialized veterinary oncology center on the west coast and in June 2016 moved here from the east coast of Florida and opened Cancer Veterinary Centers at the Naples location in the Emergency Pet Hospital. In April 2017 they opened the second location in Bonita Springs, which is a state-of-the-art cancer center to include radiation therapy.
When not treating her 4-legged patients with cancer, Dr. Kosarek enjoys spending time with her husband and their 10-year-old son. She also has 2 cats, Luke and Leia and a puppy Finn who manage to keep her busy! She likes to stay healthy with pilates and cycling, but one of her favorite things to do with her son is birdwatching!
- Bachelors of Science, University of Florida
- Masters of Science, The Ohio State University
- Doctor of Veterinary Medicine, University of Florida
- Diplomate, American College of Veterinary Internal Medicine
Board Certified in Oncology
Our Oncology Nurses
Medical Oncology Nurse
Amy is originally from Quebec, Canada where she was born. She has lived in Florida for 13 years and in that time graduated from Edison State College in 2013 with an Associate Arts degree. From there she went on to earn her Associate of Science in Veterinary Technology with honors in 2015. She is currently studying for her CVT. Amy has always been interested in animals from domestic pets to large farm animals and even reptiles. Her desire to help animals brought her to Cancer Veterinary Centers where she is a Medical Oncology Nurse treating domestic pets. Since joining the team, she is now currently in training for radiation therapy expanding her experience and responsibilities in oncology medicine.
Amy enjoys her free time with her husband and her dog Molson who is a German Shepherd. She also likes to stay mentally and physically healthy with reading, working out and having good meals!
Medical Oncology Nurse
Shannon was raised in Naples, Florida but was born in East Longmeadow, Massachusetts. While going to school for a teaching degree, she realized that her passion really was helping animals. She quickly changed career paths and focused on the general veterinary practice field. She worked in general practice for 8 years and from there went into specialty medicine and joined ER. In 2016 she moved into neurology and then into oncology where she took a special interest in. She felt this specialized area of veterinary medicine was the most challenging, yet the most rewarding. If there is any one area she could say is most intriguing to her in oncology, she would have to say brain tumors and lymphoma. Shannon’s 11 years of general and specialty experience, as well as her true passion for veterinary oncology, brought her to Cancer Veterinary Centers where she works as a Medical Oncology Nurse. She is currently studying at Penn Foster to receive her CVT license. In her personal time, Shannon shares her life with her horse Partner, Shelby her Australian Shepherd and Chitty the cat! She finds her relaxation at the barn with her family horses or doing water activities.
Medical Oncology Nurse
Michelle was born and raised in Florida. She was born in West Palm Beach, was raised in Orlando and moved to Fort Myers in 2009. She has worked in veterinary medicine since 2006. Michelle spent 4 years in veterinary internal medicine before she decided to pursue veterinary oncology. Her special interest in lymphoma in pets not only helped with that decision but is what brought her to Cancer Veterinary Centers as a Medical Oncology Nurse. She sees many patients with lymphoma successfully go into remission and do well and this is gratifying to her. As a Medical Oncology Nurse, she wears many hats and performs tasks in many areas such as; chemotherapy, CT scans, and x-rays along with doing inventory and just the day to day duties.
Michelle and her 6-year-old son enjoy their time together with their 2 Pitbulls, Dixie and Tex, an African Grey, Jessie, a turtle named Ricki and a fish named Splash. Outside of spending time with her son, she enjoys going to the beach and sipping wine!
Medical Oncology Nurse
Elizabeth, better known as Liz, was born in Naples, Florida but raised in Harlingen, Texas. In 2012 she moved back to Florida. She graduated from Heritage Institute in Fort Myers, Florida with an Occupational Associate of Science in Veterinary Technician degree in February 2017.
Liz also served in the United States Army 25th Infantry Division, HI from 2010-2013 where she was deployed to Afganistan. It was the military bomb detection dog, Dolly, that inspired her to want to become a veterinary oncology nurse. Dolly was special to Liz and just a year after deployment, Dolly got stomach cancer. After that, Liz’s goal has been to become a VTS in oncology and help future military dogs.
Her compassion for dogs and cats with cancer brought her to Cancer Veterinary Centers as a Medical Oncology Nurse where she administers chemotherapy, CT, radiographs and all other duties of a Veterinary Oncology Nurse.
In her personal time, Liz enjoys spending time with her 6-year old son, taking him to the beach and to parks. She very much enjoys outdoor activities like camping, hiking, fishing, and trail walking. In between all of that, she is training her new Australian Shepherd puppy to be an ASD Service Dog.
Andrea always wanted to be a nurse because she wanted a career where she would be making a difference in
In her personal time, she enjoys spending it with her husband, 9-year old son and their Chihuahua Nibblet. Living in Florida, she takes advantage of enjoying the beautiful beaches! She also likes to go to the local breweries and concerts.
Medical Oncology Nurse
Terri is originally from Alaska where she was born and lived until 2003. Prior to her moving to Florida in 2018, she lived in Idaho, Washington, California and Las Vegas, Nevada. It was in Las Vegas where she earned her Veterinary Assistant Certificate from Pima Medical Institute in 2014. She then passed her VTNE and received her Veterinary Technician license in the Fall of 2014.
Terri was inspired to become a Veterinary Technician simply by watching Animal Planet on TV! Watching people help and save the lives of animals was what she had a passion to do. She came to Cancer Veterinary Centers as a Medical Oncologist after 7 years in the general practice veterinary field. She wanted to be in specialty care and cancer was the specialty care she wanted to pursue. There isn’t really one particular thing she enjoys most about working in cancer specialty, she says she loves everything about treating patients. Her primary responsibilities at Cancer Veterinary Centers are the duties of a Medical Oncology Nurse, assisting with CT scans and Radiation Therapy.
When she is not treating patients at work, she is spending quality time with her 14-year old daughter and family going on road trip adventures, enjoying the beach and collecting shells as well as reading. Terri and her daughter have 2 cats of their own that are 8 and 14 years old.
Kasandra, better known as KC, is originally from Puerto Rico and has lived in Florida for 6 years. She graduated with a Veterinary Technology degree from Sanford Brown Institute in Fort Lauderdale, Florida in May 2014.
KC knew her career life was going to be helping animals since childhood. Her love and compassion for animals are what brought her to Cancer Veterinary Centers where she is a Radiation Oncology & Diagnostic Imaging Supervisor. She especially enjoys radiation therapy because she sees how well her oncology patients feel after their treatments. In her own words, she has said: “I don’t see myself in any other scenario if there are no animals involved.”
KC is a very talented artist and in her personal time, she loves to draw and paint. She has drawn many of her patients’ portraits as gifts to their owners. Her work is just beautiful with every such detail. Her own rescued dog, Rizzo and cat Khalee also keep her busy! KC enjoys spending some relaxation time with friends, enjoying the pool, beach as well as road trips.
Veterinary Nurse Assistant
Jessica (Jess) is a native to Florida originally from Fort Lauderdale. She originally joined Cancer Veterinary Centers as a Client Service Representative then moved into working as a Veterinary Nurse Assistant where she assists our Veterinary Oncologists as well as our Medical Oncology Nurses with the day-to-day care of patients. Her care for our patients and willingness to assist our medical team is appreciated in all departments of Cancer Veterinary Centers.
In her personal time, Jess is very busy with her 2 sons and the various pets they have; 3 dogs, 3 cats, 3 tortoises, 2 snakes, a bearded dragon and 2 turtles. Jess will tell you that in her free time she enjoys tie with her boys, cleaning and taking her children from one sports practice to another!
Our Client Service Representatives
Customer Service Representative
Dena is originally from Connecticut and has been in Florida since 1991. She received her medical assistant certificate from Edison Community College in Florida. Through the U.S Career Institute, she received her certificate in medical coding. As one of Cancer Veterinary Centers Customer Service Representatives, her smiling face greets our patients as they walk through the doors. Dena’s 20 years of experience in the human medical field as a CSR and her love of animals brought her to Cancer Veterinary Centers. Her natural talent for such friendly and sincere compassion for clients and patients is a warm feeling upon arrival and departure. She is also one of the pleasant voices on the other end of the phone when our clients call our office.
Dena spends time with her 15-year-old and their dog Oreo who is a border collie mix. She enjoys relaxing with a bike ride, shopping or going out to dinner with family and friends. One of her most interesting hobbies is attending fan conventions where she gets the opportunity to meet her favorite actors! It is there that she collects celebrity items, autographs, and pictures with the celebrities.
Customer Service Representative
Karen is originally from the Twin Cities MN and lived in Colorado for 12 years before moving to Florida in 2013. She has joined Cancer Veterinary Centers as a Client Service Representative where she assists in the welcoming and caring customer service we pride ourselves on. Karen’s love for animals since a little girl comes through to our clients as they walk through the front doors. With a warm tone in her voice and smile on her face, our clients are happy to walk through those doors! Karen is also an on the job trained Vet Assistant, so when she is not checking our patients in at the front desk, she is assisting with their needs in the back.
In her personal time, she loves to spend as much time as she can with her 7-year old Jack Russell, B.G., 10-year old chihuahua, Kodi Bear and 1-year old cat, Mick. She also enjoys walking the beach, swimming, kayaking and catching up with friends and family in Colorado and Minnesota.
Our Office Administration
Ellen was born in Texas but moved around quite a bit in the U.S as well as Europe. She settled in Florida 1 ½ years ago. She received her Bachelor’s degree in pre-veterinary medicine from the University of Delaware and her Master’s degree in biomedical and genetic engineering at Drexel University and Villanova. She then went on to get her MBA from Penn State University.
Ellen has worked full time in general veterinary medicine for 20 years. Her passion to spend her career life in the veterinary industry started at the age of 12 when she worked in veterinary practices in the kennels and on horse farms. Ellen worked as a veterinary technician and moved into a practice management position. She brings 21 years of experience to Cancer Veterinary Centers in her role of the Practice Manager. Her extensive veterinary knowledge and ability to manage a team of employees with harmony is a strength for Ellen. There is no such thing as a “typical” day for Ellen and her easy-going personality lends itself well to keeping each department running smoothly each day. There is not an area of the practice she cannot assist with at any given time.
When she isn’t managing the practice, Ellen is managing her own time enjoying it with her 7-year-old son and their pets that consist of a Yorkie, 1 adult cat, 2 kittens, and a macaw. She enjoys being physically active by going to the gym, weight lifting, playing pickle ball and tennis. For relaxation, she likes to go boating and having brunch with friends.
Human Resources Administrator
Jennifer (Jen) was born in St. Petersburg, Florida but raised in Sonoma County, California. She raised her family in Tallmadge, Ohio before she just relocated back to Florida to be closer to her family in North Fort Myers in June 2018.
Jennifer received a Bachelor of Arts degree from Kent State University with a focus on Paralegal Studies and a minor in Human Resource Management as well as an Associates of Arts degree in Human Resources Management. She was nationally recognized as an HR Professional in 2016 by the Society for Human Resources Management.
While in Ohio, she worked as the Human Resource Generalist with the Ohio Department of Youth Services for 8 years, then as a Human Resource Senior Analyst and Manager over three counties with the Ohio Department of Transportation for the past 7 years.
It’s Jennifer’s passion for helping and teaching people that brought her to Fetch Specialty and Cancer Veterinary Centers as the Human Resources Administrator. She will tell you that “through career counseling and developing training plans with employees, I share in the pride with an employee who has reached their goals and potential.” It is Jennifer’s responsibility to ensure that employees have consistent, fair and impartial hiring practices while maintaining the legal requirements of payroll and employment document management.
Jennifer has a 22-year old son who is an Air Force Staff Sergeant and a 24-year old daughter who is a Social Worker. In her personal, quiet time, she enjoys painting, reading, and gardening. She also takes time to enjoy the Florida beach, good food, and wine and some traveling. She also volunteers at her church and for the Gulf Coast Humane Society.
Marketing Outreach Coordinator
Alesia is originally from Syracuse, New York and has lived in Florida for 26 years. She brings with her over 15 years of experience in the marketing and sales industry. She comes to Cancer Veterinary Centers from the Country Club business, where she served as a Director of Sales and Marketing for 15 years.
For the last 10 years, she has also served as the President and founder of Golden Retriever Rescue of Southwest Florida, Inc. It is through the rescue Alesia first met Dr. Kosarek and Dr. Ratterree and a good working relationship between Cancer Veterinary Centers and the rescue began. Alesia comes to Cancer Veterinary Centers with a great passion for animals and good medical knowledge as a medical coordinator for the rescue. Through the rescue, she has also developed good working relationships with many of the local veterinarians in the area.
Alesia manages the outreach and community engagement activities of Cancer Veterinary Centers. She keeps all of the local veterinary hospitals and pet owners up-to-date on all that Cancer Veterinary Centers has to offer their patients and pets in cancer care.
When she is not bringing awareness to the community about Cancer Veterinary Centers, you will find her working hard in the Golden Retriever Rescue of Southwest Florida. She also spends as much time as possible with her husband and their 4 dogs; Bo, Riley, and Stormy who are golden retrievers and Monty a yellow lab.
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