Meet Our Team

Get to know your team at Mission Viejo Veterinary Hospital, partners for life in providing for your pet’s health and well-being. We’re committed to providing exceptional veterinary care to your cats and dogs, and outstanding service to you.

Our Veterinarians

Dr. Bruce Louderback, DVM


Dr. Louderback earned his degree from the University of Illinois.  Upon graduation, he worked in mixed practices in Vermont and Illinois before establishing Mission Viejo Veterinary Hospital in 1976.  Dr. Louderback is well-known in the veterinary community and has served his profession in many ways over the years.  He was appointed by Governor Bill Owens to sit on the Colorado State Board of Veterinary Medicine and served two terms from 1999 to 2007.  His contributions to the state board led to involvement with the National Veterinary Board where he has served as Director, Secretary, Treasurer, and President.  in 2009, Dr. Louderback was honored to be elected Colorado Veterinarian of the Year.  He and his wife, Jody, have three grown children and two grandchildren.

Amanda Berry, DVM


Robert Moore, DVM


Dr. Adam Ralston, DVM


Dr. Ralston is a Colorado native who received his Doctor of Veterinary Medicine from Louisiana State University in 2002.  He has worked part-time with Mission Viejo since 2007.  Dr. Ralston lives in Thorton with his girlfriend Carly and their two orange tabby cats- Tucker and Hillstead.   While he only boasts furry children, he has two nieces and a nephew that he loves spending time with.  At work, ophthalmology is of particular interest to him and we get the benefit of his surgery skills when he fills in on occasion.  Dr. Ralston spends his free time exploring our wonderful state tent-camping, biking, hiking, rock climbing, and taking pictures of local wildlife and landscapes.  He also enjoys traveling and exploring national parks with Carly.

Dr. Karalee Gendreau, DVM


Dr. Gendreau began working part-time for Mission Viejo Veterinary Hospital in 2009 after graduating from Ross University School of Veterinary Medicine in 2005.  She and her husband, Tom, have two Bernese Mountain Dogs named Jameson and Brinley.  She has a passion for animal welfare causes and a special interest in working dogs and animal behavior.  Dr. Gendreau nurtures a strong doctor-client relationship; she believes that superior client education fosters a healthy human-animal bond and allows owners to be able to relate to their pets more easily. Dr. Gendreau also volunteers her time as a member of the Colorado Veterinary Medical Reserves, so animal-related endeavors take up a lot of her time.  When she is not on the job, she enjoys exploring the mountains of Colorado with her husband and dogs.

Dr. Delio Tamayo, DVM, MA


Born and educated in Manizales, Colombia S.A.  In the waning days of 1970, he emigrated to the US with his wife and infant daughter.  In 1972 he became the first foreign-educated veterinarian to be licensed in Colorado.  He owned and operated Altos Veterinary Clinic for 30 years. Dr. Tamayo has held multiple leadership positions in both the metro area and the state Veterinary associations. He is the only Hispanic veterinarian so far to serve on the Colorado State Board of Veterinary Medicine, chairing it for 6.5 years, and received the distinguished service award from the Colorado Veterinary Medical Association, this association’s highest honor.  Dr. Tamayo has devoted much of his time to serving the Hispanic community by being a founding member of Fraternidad Hispana de Colorado, serving on the Colorado Quincentenary Commission, and was the first and only Latin American Immigrant so far to serve on the Colorado Civil Rights Commission. He was the Director and producer of Festival of the Americas for 13 years and is a member of the St Joseph’s Hospital Bioethics and Social Justice Committee. Dr. Tamayo has also hosted radio programs and was a newspaper columnist.




Deann graduated from the University of Northern Colorado in 1982. She started at Mission Viejo Veterinary Hospital in 1984 as a veterinary receptionist, and since 1995 she has been our office manager.  A position she really relishes, as her job is never the same day-to-day.  She especially enjoys researching new medications for our patients and talking with clients about their pets and their unique dietary needs.  You may see her filling in for the front staff from time to time; it gives her a nice break from the paperwork involved in managing our hospital.  During her time off, Deann enjoys our beautiful Colorado weather with her Afghan Hounds at various performance events, like lure coursing. She is also a sports enthusiast- she loves baseball (Go Rockies!) and football (Go Broncos!)

Support Staff

Christina, CVT


Christina started working at Mission Viejo Veterinary Hospital in 2014 while attending Bel-Rea Institute of Animal Technology. In 2016 Christina graduated with an Associate’s Degree in Applied Science and is a Certified Veterinary Technician. She is very compassionate about the well-being of animals and the happiness of their owners.  Christina is tasked with supervising our kennel staff and looks forward to her interaction with our boarding pets. She enjoys the opportunity to learn new things in the veterinary field and staying up to date on current education. Christina was born and raised in Aurora, CO, and enjoys spending time with her family and friends, adventures out of doors, and good movies!  She always knew growing up that she wanted to work with and care for animals one day. She fulfilled her passion for animal care that she developed through her love for her dogs Chewbacca, Magellan, and various pets she and her family had over the years. Currently, she has her dog Mitzi that helps her every day along with her cat Henry, guinea pig Trey, fish Blue and new addition to the family Luna. 

Kerriann Exner


Kerriann (Kerri) has been with Mission Viejo Veterinary Hospital since 2006.  Kerri is a CVA and is working toward a Canine Behaviorist Certification.  She has spent her life working with all dog breeds and has a special bond with large breeds especially Bullies and Mastiffs.  Kerri has raised and trained many Cane Corso’s, American Staffordshire Terriers, and American Bull Terriers.  She is our go-to person for assisting our bigger friends. Kerri shares her home with  Athena a Staffordshire Terrier and Kodiak a Cane Corso.

Raylene Lopez


Raylene has always loved working with animals and we gratefully welcomed her to the Mission Viejo Team in May of 2021. She absolutely loves meeting new people and talking with them about their pets.  Raylene shares her home with two cats, Myla and Garfield, and 3 dogs Lola, Cali, and Monta.  When not at work, she enjoys spending time with her boyfriend of 9 years, her 3 daughters, and her son. 

Cynthia Roybal


Michelle Salaz


Michelle is a Colorado native and started her journey as a veterinary assistant in 2019 and found her home with Mission Viejo Veterinary Hospital in 2020.  Michelle’s bubbly attitude makes both pet parents and their fur babies comfortable while in her care. Michelle has gladly taken on the responsibility of caring for her grandparent Basset Hounds, Sonny, and Cher and outside of work, Michelle loves to explore the outdoors with her Labradoodle, Bumpers.  She also enjoys reading a good book and watching movies in her free time. 

Trevor Nielson


Christa Sanchez


Michelle Gilger


Michelle is a Colorado native and has been living in the Mission Viejo neighborhood since 2001. She loves Colorado so much and enjoys hiking, camping, and the occasional backpacking trip with her two children. They share their home with a Saint Bernard, a Miniature Pinscher, a cat, and 4 Guinea Pigs. In her free time, Michelle likes to crochet, sew and refurbish furniture.  Michelle is a stand-out Customer Service Representative that enjoys greeting all our pet parents and their fur babies.