Our caring and compassionate veterinary care team!

Meet the Veterinarians of Risinger Veterinary Hospital in Terrell! We’re pleased to provide exceptional vet care for your pets!

Please call us at (972) 563-3305 to speak to one of our caring veterinary staff members!

Casey Risinger, DVM/Owner


Dr. Casey M. Risinger has been around veterinary medicine his entire life. He grew up following his veterinarian father, Dr. M.L. Risinger, at his vet clinic in Kaufman and later in a mobile large animal practice in the Terrell area. Dr. Casey graduated from Terrell High School then attended Texas A&M University, graduating from Texas A&M College of Veterinary Medicine in 1986. After practicing in Vernon for 1 year, he moved back to Terrell and opened Risinger Veterinary Hospital in June 1987. He and his father practiced together until Dr. M.L. Risinger passed away in 2003. Dr. Casey is married to Phyllis and they have 6 children: Rebekah, Rachel, Mitt, Marty, Casey Dean and Court, and 1 grandson: Joshua Casey Garza. The family attends church at First Baptist Church in Terrell. His hobbies include raising cattle and following his kids around.

Megan Harris, DVM


Dr. Megan (Kirkland) Harris is a hometown girl from Poetry, Texas. She previously worked as a veterinary technician here at Risinger Veterinary Hospital after high school. She received her Bachelors Degree in Animal Science from Texas A&M University – Commerce and is a veterinary graduate of Texas A&M University College of Veterinary Medicine. She married childhood friend, Justin Harris in 2012 and the couple now has 2 boys, JW and Jo Luke. Dr. Megan brings her dachshund, Ruger, with her to work every day and enjoys the family’s many coon dogs and horses at home. When she’s not at work, she values time with her family, ranching and running. The family attends Kaufman County Cowboy Church in Kaufman, Tx.

Kerri McMahon, DVM

Monday, Wednesday and Thursday

Dr. McMahon attended Texas A&M University and graduated from veterinary school in 1999.  She grew up and went to school in Royse City, but since graduating vet school has practiced in Arizona on the Navajo Reservation, in Colorado on the western slope of the Rockies, and in southern California.  Her love for all things Texas brought her home in 2011.  Dr. McMahon really enjoys time with any type of animal with a particular passion for illness and internal medicine in any species. Dr. McMahon loves being a vet and also loves her family time with Tim and their daughters, Hannah and Riley.  The family lives on a small farm in Wills Point surrounded by an ever growing tribe of animals large & small.  The whole family enjoys riding horses, reading books, camping, and a good bonfire.  Cornerstone Church of Rockwall is the McMahon family’s church home.

Dr. McMahon invites you to come by and say hello, even chat a while.  She feels blessed to be part of the Risinger Veterinary Hospital family.

Lisa Dunn, DVM


Dr. Lisa has been practicing small animal medicine in the DFW area since graduating from Texas A&M University College of Veterinary Medicine in 1986. She received her undergraduate degree in Animal Science from Texas Tech University. She is originally from the Midwest and moved to Texas in her teen years where she graduated from Hillcrest High School in Dallas. Her husband, Wade Dunn, is from the Texas Hill Country and is also a veterinarian practicing in East Dallas. The two actually graduated in the same veterinary class as Dr. Casey. Dr Lisa and her husband have lived in Rockwall since 1999. They have three children, Gill, T. Walker, and Lillie as well as two dogs and three cats. They are members of Rockwall Presbyterian Church where the family takes an active part in the community. Her hobbies of running, gardening, antiquing, reading and sewing have gradually become sidelined until all three of their teenage children head off to college.