Cassie Quillen, DVM; Owner

Dr. Quillen is originally from southcentral Minnesota.  She graduated from Iowa State University with her Bachelor of Science in 2007 and her Doctorate of Veterinary Medicine in 2013.  Since graduation, Dr. Quillen has worked in small animal practices in central Iowa and southeastern Minnesota; becoming a partner of ZVC in 2022 and full owner in 2026.  She is a member of the AVMA and the MVMA and has received additional training in dentistry and ultrasound.  Dr. Quillen's professional interests include preventative care and internal medicine.  In her free time, Dr. Quillen enjoys spending time outdoors with her husband and two children.  She has two dogs, a hound dog mix named Moxie and a Chihuahua named Lulu, and a couple of kitties, Mika and Sylvie.

Kate Mathes, DVM

Dr. Mathes joins ZVC from her home state of Iowa, where she attended Morningside College, graduating in 2017 with a double major in biology and chemistry. Her next step was to Iowa State University, where she received her Doctorate of Veterinary Medicine in 2021. After practicing in a mixed animal clinic for a few years, she found her passion in caring for companion animals.  Dr. Mathes' professional interests include dermatology and internal medicine. In her spare time, Dr. Mathes enjoys spending time with her family and their ever-growing fur family.

Dan Nietz, DVM; In-house Surgeon

 Dr. Nietz received his Bachelor's degree in Biology from Luther College in 1996, and is a 2001 graduate of the University of Minnesota College of Veterinary Medicine.  Dr. Nietz has furthered his veterinary education with additional training in orthopedic and soft-tissue surgery, and advanced dentistry.  He began working at ZVC in 2002 and had been owner of Zumbrota Veterinary Clinic since 2004. In 2026 he handed the ownership reins over to Dr. Quillen. He continues to provide his surgical expertise to the clinic each week.