Our Hospital remains open 24 hours a day for your pet’s needs. During this difficult time in our community the first priority is the health and safety of your families and ours while providing excellent care to meet your pet’s medical needs. We have instituted new hospital protocols based upon CDC recommendations. Please give us a call if you need any assistance.  Stay Healthy and Stay Safe.

Our Doctors

Cynthia Duesberg, DVM, DACVIM

Dr. Duesberg

Diplomate, American College of Veterinary Internal Medicine

DVM: University of California, Davis
Internship: Cornell University
Internal Medicine Residency: University of California, Davis

Dr. Duesberg received her veterinary degree from U.C. Davis in 1989.  Upon graduation, she was selected for an internship with Cornell University.  She then completed a 3-year internal medicine residency at U.C. Davis. Following her residency, she served as a U.C. Davis faculty member, instructing both students and residents. She left academia for private practice and has been serving the needs of clients and patients in Southern California since 1996.  As a board certified internist, she has advanced skills in the areas of endocrinology, gastroenterology, hematology, infectious diseases and urology.  She has lectured locally and nationally, and has been published in leading veterinary journals and textbooks. Her detailed and caring approach to each individual client and patient has made her your trusted referral partner of specialty internal medicine care. Dr. Duesberg founded AVIM in September of 2011.

Kerrie Chung, DVM

Residency Trained in Internal Medicine

DVM: Tufts University
Internal Medicine Residency: Advanced Critical Care & IM

Dr. Chung graduated from Tufts School of Veterinary Medicine in 1999. After working in general practice for several years, she completed her internal medicine residency in 2008. Dr. Chung’s background in general practice, together with her specialization in internal medicine gives her a wide range of knowledge and a uniquely balanced approach to specialty practice. She brings her enthusiasm and love of internal medicine to each special client and patient that she sees.

Victoria Vorathavorn, DVM, DACVIM

Diplomate, American College of Veterinary Internal Medicine

DVM: Michigan State University 2006
Internship: Veterinary Medical & Surgical Group
Internal Medicine Residency: Advanced Critical Care & IM and Los Angeles Veterinary Specialists

Dr. Vorathavorn has clinical interests in all aspects of small animal veterinary internal medicine with special interests in gastroenterology and endocrinology. She is skilled in ultrasonography and endoscopic procedures, including gastroscopy, rhinoscopy, bronchoscopy, and cystoscopy.  In her spare time, Dr. Vorathavorn loves spending time with her family and friends, traveling, and taking her dog to the beach.

Michelle Cieplucha, DVM

Residency Trained in Internal Medicine

DVM: Colorado State University
Internship: Veterinary Referral and Emergency Center, Norwalk, CT
Internal Medicine Residency: Michigan State University

Dr. Cieplucha obtained her veterinary degree from Colorado State University in 2002. She returned home to the east coast to complete an internship in small animal medicine and surgery at the Veterinary Referral and Emergency Center in Norwalk, CT in 2003. Dr. Cieplucha completed her residency in small animal internal medicine at Michigan State University in 2006. After completing her residency, she returned to Connecticut to work at VCA Shoreline Veterinary Referral and Emergency Center in Shelton, CT.  In addition to practicing full time within the internal medicine department, Dr.Cieplucha served as the President of the Fairfield County Veterinary Medical Association.

Claude Lessard, DVM

EXTENSIVE TRAINING IN Emergency and Critical Care


Dr. Lessard graduated from vet school in 2006 from the University of Montreal. She moved to California for her internship right after graduation and has never looked back since! She has found her niche with practicing Emergency and Critical Care for the last 10 years and takes a special interest in trauma cases and toxicities, as well as transfusion medicine and stabilizing respiratory and kidney disease. She currently lives with her 3 dogs, 1 cat and 2 parrots.


Laura Najman, DVM, DACVECC

Diplomate, American College of Veterinary Emergency and Critical Care

DVM: University of California, Davis

Dr. Laura Najman received her DVM in 1999 for UC Davis, and then proceeded to enter into an internship in both medicine and surgery at the Animal Medical Center of New York. Upon completion, she decided to come home to Southern California to begin a residency program in private practice, receiving her Diplomate status in Emergency and Critical Care in 2006. Dr. Najman has numerous career achievements including serving on the credential committee for the Emergency and Critical Care College, writing extensively on rattlesnake envenomation, and training multiple residents to further their goals of achieving Diplomate status. She has always taken a special interest in managing septic and critically ill patients as well as helping to stabilize patients in diabetic crisis. 



Directly Left of The Metro Station Entrance





Please walk in the front doors and check in at the 1st desk on the left.



Our specialists have a combined 50 + years of experience in Internal Medicine.



Providing in house diagnostic imaging and procedures helps us take a more proactive approach to diagnosing and treating your pet.


Advanced Veterinary Internal Medicine
2965 Edinger Ave.
Tustin, CA 92780

Business Hours

8 AM - 6 PM

Contact Us

Phone +
Fax +
Email +
This email address is being protected from spambots. You need JavaScript enabled to view it.

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.