Meet the Carlsbad Animal Hospital Veterinarians

Dr. Dennis Derieg

Part-Time Surgical Consultant/Surgeon

Dennis grew up both in Denver, Colorado, and on a farm in Nebraska. His path to veterinary medicine was somewhat accidental—he attended college on an athletic scholarship, and while there, checked out the Veterinary Medicine program and became intrigued!

Dr. Derieg used to own his own veterinary practice before he retired. He had hired Carlsbad Animal Hospital’s current owner right out of veterinary school, so when he retired from full-time work Dennis decided to help out his former employee part-time. He consults on surgeries, which had been his primary interest when he had his own practice. Dr. Derieg says the younger vets are loads of fun and help keep him up-to-date on the latest veterinary news!At home, Dr. Derieg lives with his wife, who enjoys rescuing sick animals and nursing them back to health. They have three grown children and three wonderful grandchildren. Most of Dennis’s interest revolve around his grandkids’ sports and hobbies, but he also likes to swim, play golf, and ride his bike. He also enjoys working out in the yard and reading.

Dr. Rachel Kagan


As a child, Rachel was very interested in medicine and always wanted to help animals live long and healthy lives. She knew she was too tall to be a jockey, so she decided to become a veterinarian!

Dr. Kagan grew up in Sherman Oaks, California, and started working in a veterinary hospital when she was 16 years old. She attended UC Berkeley to major in biological sciences before transferring to Cal Poly SLO, graduating in 1992. She went to the University of California Davis’s School of Veterinary Medicine and graduated in 1997. After a year-long internship in San Diego, she stayed in the area to work. In 2003, on a recommendation from her husband, Dr. Kagan started at Carlsbad Animal Hospital.Dr. Kagan loves client interaction—she enjoys taking care of animals and learning about their families in the process. She likes to think of herself as a friend to clients, not just a doctor.At home, Rachel lives with her husband John, a veterinary internal medicine specialist, and their children Cassidy and Nate. They have two dogs, Tucker and Cam Newton; two cats, Jack Sparrow and Booker; two guinea pigs, Patrick and Teddy; a crested Gecko named T Rex; a ball python named DJ; and Sydney the horse.Between her family and work, Dr. Kagan says she doesn’t have much time for hobbies. When she does have a spare moment, she loves horseback riding, yoga, and walking and hiking with her husband and friends.

Dr. Tom Livezey


As a young boy, Tom Livezey once swam to rescue his friend’s dog who was struggling in an ocean rip current. The sense of pride he felt, coupled with his friend’s relief and joy, inspired Tom to become a veterinary professional!

Dr. Livezey worked full-time in a research lab and part-time at a veterinary practice after he graduated college, and then was accepted to the University of Pennsylvania’s Veterinary School. He graduated with his DVM in 1998 and moved to California with his wife after living on the East Coast his entire life.Supporting the human-animal bond between pets and owners is Tom’s passion within veterinary medicine. He also likes abdominal ultrasounds, internal medicine, and dentistry.In his spare time, Dr. Livezey enjoys spending time with his family—watching their enthusiasm and love of pets brings him great joy! He also likes playing tennis, surfing, and spending time at the beach.

Dr. Candace Runyan


Candace grew up in the San Fernando Valley and had always dreamed of becoming a veterinarian. She was taught from an early age to have respect and love for animals. After working in sales for a few years, Candace decided to go back to school, and now follows her passion as a Veterinarian at Carlsbad Animal Hospital!

After receiving a Bachelor’s degree in Communication from San Diego State University, Candace worked in the hotel industry for a few years. She made the decision to go back to school, graduating from Ross University School of Veterinary Medicine in the Caribbean. After a clinical year at Louisiana State University, she moved back to San Diego and recently started at Carlsbad Animal Hospital after completing a rotating internship.As a veterinarian, Candace particularly enjoys emergency medicine and surgery. Both can be stressful, but Candace loves the fast pace and attention to detail!At home, the animals in Candace’s house outnumber the humans. She lives with her boyfriend Allen, an aspiring veterinary dentist, and their three pets. Sebastian and Simon are their two cats, and Gus is their dog who knows a lot of tricks except coming when he’s called.Candace and her boyfriend like to spend time outdoors, running, biking, hiking, and playing volleyball. Candace loves setting personal fitness goals—it started with her first marathon, the La Jolla half marathon. She says her next feat will be a triathlon!

Dr. Chelsea Warren