Cerritos Veterinarians

We invite you to explore the biographies of our doctors and learn more about them. Our doctors have a wide variety of backgrounds and interests.

  • Ronald Morein

    Medical Director
    Veterinary School: University of California, Davis

    Dr. Ronald Morein graduated from the School of Veterinary Medicine at the University of California at Davis in 1966. He entered private practice in the San Gabriel Valley working primarily with dogs and ...
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  • Denise Bierens

    Staff Veterinarian
    Veterinary School: Ross University School of Veterinary Medicine

    Dr. Denise Bierens was born and raised in Canada. She went to veterinary school at Ross Uiversity and completed her clinical training at the University of Missouri. Dr. Bierens worked for two years at ...
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  • Ryan Smith

    Staff Veterinarian
    Veterinary School: Western University of Health Sciences
    Graduate School: University of Minnesota, Twin Cities

    Ryan Smith graduated from the College of Veterinary Medicine at Western University of Health Sciences. Following veterinary school, Ryan completed a 1-year rotating internship in small animal surgery and ...
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  • Stephanie Zinsser

    Staff Veterinarian
    Veterinary School: University of Pennsylvania

    Dr. Stephanie Zinsser graduated from Cornell University with a Bachelors of Science in Animal Science with a focus in reproduction and research.  She attended the School of Veterinary Medicine

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