Equine Staff: Individual attention with support of the entire staff!

Richard L. Stevens, D.V.M.

Dr. Stevens graduated from CSU in 1981 and joined Conejo Valley Veterinary Hospital as an intern that same year. Dr. Stevens is married with two children.

His menagerie includes numerous dogs and the best stray farm cat. He enjoys skiing and mountain biking with his family as well as raising guide dogs for the blind.

Dr. Stevens professional interests include Sports Medicine, Equine Reproduction, and Equine Dentistry..


Merle DerVartanian, D.V.M.

Dr. Merle received her B.S. and D.V.M. degrees from University of Georgia,

in Athens, Georgia, and completed her internship at Chino Valley Equine Hospital. In her free time, Dr. Merle enjoys riding, running, cycling, and hiking with her dogs Paulie and Emmy.

She also enjoys spending time with her four-legged hooved animals which include two horses, two donkeys, and now a mule.

Dr. Merle’s professional interests include ophthalmology, internal medicine, wound management, lameness, and geriatric care.


Kristen Brown, D.V.M., C.V.A.

Kristen Brown completed both her undergraduate and veterinary education at the University of California Davis. Following graduation she did a one year internship at B.W. Furlong and Associates, an equine hospital in New Jersey. She gained certification in equine acupuncture from the Chi Institute of Traditional Chinese Veterinary Medicine. Following her internship Kristen returned to northern California and worked for 2 years at an ambulatory equine practice in Chico before joining the staff at Conejo Valley Equine.

She enjoys riding, hiking, and exploring with her dog, Sansa. Kristen loves all aspects of veterinary medicine, but especially enjoys emergency medicine and lameness cases, as well as developing relationships with her patients.

Carin Zeller, D.V.M.

Dr. Carin Zeller completed her veterinary degree at the University of California- Davis in 2016. She served as a veterinarian in the United States Army for 5 years- taking care of the Military Working Dogs and Horses. She was stationed in Texas, California, and Washington DC. Her final assignment was taking care of the 70 horses who carry service members to their final resting place in Arlington National Cemetery.  She gained certification in equine rehabilitation through the University of Tennessee. Her professional interests include emergency medicine, lameness, and rehabilitation.

Dr. Zeller enjoys riding, running, weight lifting, and spending time with her family; which includes her husband- Tyler and two dogs- Annie and Jessie. 

Hayley Rasmussen-Ball, D.V.M.

Dr. Rasmussen-Ball earned her Bachelor of Science degree at the University or Nevada, Reno in the same town where she grew up. She completed her veterinary degree at Washington State University. Following veterinary school, Hayley completed a yearlong internship at Alamo Pintado Equine Medical Center in Los Olivos, California and subsequently stayed with the clinic to complete a fellowship in the Internal Medicine department.

Hayley enjoys all aspects of being an equine veterinarian but is particularly interested in internal medicine, nutrition, and neonatal care.

Hayley and her husband Brian love spending time with their son and their animals. They enjoy trail running, hiking and exploring the West Coast.