Everyone at Tillema Veterinary Clinic takes pride in their work. We love animals and use our knowledge and compassion in the treatment of every patient we see. Helping your pet live a happy and healthy life is why we come to work each day so we welcome you to stop and see what we have to offer.


Dr. Tillema, DVM

Dr. Tillema grew up on a dairy in a small town in West Texas. Dr. Tillema served in the United States Navy and then when his tour ended, he began his studies to become a veterinarian where he worked three jobs and went to school. Dr. Tillema began practicing veterinarian medicine in upstate N.Y. where his patients were big and small. He soon moved to California where he opened his own mixed practice as a mobile unit. Seeing that he was limited on what he could do for his small animal clients, Dr. Tillema opened a small animal practice in Corona. Dr. Tillema was injured by a bull and acupuncture was the only pain of relief that he had, after that incident Dr. Tillema studied acupuncture at the Chi Institute where he found that Western and Eastern medicine worked better together than any one alone. Dr.Tillema also has an interest in orthopedic medicine as well as general practice. When the Doctor isn’t working he enjoys skydiving, zip-lining, hiking, fishing, barbeques and watching and playing sports.

Dr. Olmstead, DVM

Dr. Olmstead is our relief veterinarian here at Tillema Veterinary Clinic. She graduated from Ross University in 2006, and then went on to do a year internship with Willamette Valley Equine where she was hired on as an associate. Dr. O spends her free time with her four horses and two dogs. 

Maria, RVT

Maria graduated from Mt. San Antonio College with an Associate of Science Degree in Animal Health Technology. She has been a licensed Registered Veterinary Technician for 20 years. She has practiced in a variety of fields ranging from small animal hospitals to research and development. Prior to joining the Tillema Veterinary Clinic team, she worked for 12 years at an emergency and critical care facility. She has a large and varied family of pets in her household including dogs, cats, tortoises, rabbits, a chinchilla, a bird and a frog. Maria enjoys attending karate tournaments with her husband, son and daughter as well as collecting succulents and cacti and photography.

Sandra, Veterinary Assistant

Sandra has been working in the veterinary field as an assistant for 8 years. She gained extensive knowledge during her time with the FFA, where she showed multiple large animal species including cattle, sheep, goats, and pigs. She also served as her chapter's president two years in a row as well as taking home a master showman title. Sandra has been showing competitively in the horse show industry since she was 10 years old, and her pride and joy is her appaloosa gelding. The two of them showed and won multiple local championships and national titles during their time in the ring. During her off time she enjoys the company of her labrador along with her friends and family. 

Jenn, Veterinary Assistant

Jenn graduated from Carrington College with an Associates of Science in Veterinary Technology in 2017. She has been involved in the equine industry for over 10 years and has shown on the breed show level and open circuit as a youth rider resulting in multiple year-end championships and circuit awards. She has two BLM mustangs, one of which she competed with in the 2009 Extreme Mustang Makeover in Norco winning 10th overall.  Jenn shares her life with her husband, six miniature dachshunds(yes, SIX!), two horses, a goat, and two guinea pigs. In her spare time, she enjoys crossfit, running, and hiking.

Jenelle, Veterinary Assistant

Jenelle is in her second year at Cal Poly Pomona where she is studying pre-veterinary/animal science. Jenelle is working toward becoming a mixed animal practice veterinarian. When she is not studying or working at a diary, Jenelle likes to hang out with her three dogs, three cats, and two birds as well as hiking and being outdoors. 

Krystal, Client Care Specialist

Krystal has been in the veterinary field for two years. She was born and raised in Corona, CA where she and her boyfriend put down roots and adopted their dog at three months, their furry family member is now three years old. Krystal is a self proclaimed "obsessed dog mom" and showers her fur-child with love and treats. The newest addition to her family is a four week old black kitten. When Krystal isn't at the clinic she enjoys visiting the Oregon coast, BBQing with friends and family, camping, and sitting by the campfire with a glass of wine.