Dr. Dayton Williams, DVM

Dr. Dayton, was raised on a farm outside of Madison, SD. As a child he would care for and mend injured animals, like deer, ducks, and pheasants.

In 1986 he graduated from Iowa State University and interned at both Kansas City Zoo & Houston Zoo. For two years he practiced in Marshall, MN in a mixed animal hospital. Following that position he worked at Valley Animal Hospital for another two years and started practicing at the Great Plains Zoo.

Dr. Williams opened All Animal Pet Hospital in 1990 and continued working at the zoo. He specializes in exotic medicine and small animals.

Dr. Dayton and his wife Tracy, have one daughter, Kerri and two sons: Trayton and Dalton, many chickens, 3 goats, 2 dogs: Mauii and Ava, one cat named Rainy and one turkey named Tom.

Lindsey McDonald- Certified Vet Tech

Lindsey started working with us about one year ago. She began her internship with an All Animal Pet Hospital. Upon completion of her internship we offered her a full time position. Lindsey graduated from college December of 2016. She has two guinea pigs, one bunny and a cat!

Abby Ontjes

Abby Ontjes – Certified Vet Tech

Abby started working with us in 2016. Prior to that she worked in a Large Animal practice for 2 years. Abby graduated in 2013 and received her certification followed by an internship at the Great Plains Zoo with the keepers and loved working with the goats and ewes! Abby has 3 dogs, 3 cats and 3 chinchillas at home. She loves to learn more ways to help animals and one day wants to have her certification in physical therapy.

Emma – Veterinary Assistant

Emma started working with us in 2013. She graduated High School and is in the Pre Veterinary program in Aimes, IA. She has also been interning at the Great Plains Zoo and is a Jr. Zoo Keeper.

Emma is in marching band as a section leader and is an aspiring veterinarian. She volunteers at the Humane Society, owns two dogs, two cats, two hamsters and two birds.

She loves drawing!

Jade Heilman

Jade started working with us in August 2019. She graduated in 2019 from SDSU with a bachelor degree in Biology and pre-veterinary medicine and minors in animal health and theatre. She has a dog and a cat (who thinks he is a dog) at home. In her free time, she likes to knit and watch plays and musicals. This is her first veterinary job.


Katelynne started working with us in Dec of 2018. Prior to that she worked as a dog trainer at PetSmart and was kennel staff at the humane society. She also had a seasonal job the Great Plains Zoo. She was a Seasonal Educator for three summers and was a Seasonal Zoo Keeper for a summer. She also did an internship at the zoo. Katelynne graduated in 2016 with an Associates degree in Ag Science and graduated with a degree in Psychology in 2018 (with an emphasis on animals). Katelynne has 2 dogs, 2 guinea pigs, and a chinchilla at home. She loves having the opportunity to care for exotic animals.


Lisa started working with us in March of 2019. Ever since she was little, she knew she wanted to take care of animals. Bringing home every injured animal she could find to help heal it and release it back into the wild. Starting college in 2015 as a vet tech, she graduated in 2019 with an Associates Degree in Business. Although she was a business degree, she never stopped helping animals in need. The opportunity came to work with us and she has been happy here ever since. Taking care of three dogs at home as well as working here she spends everyday with all different types of animals, there is never a time the she is not with an animal.

Mandy MacGregor

Mandy was born and raised in Norfolk, VA and lived in Texas for two years before moving to Sioux FAlls. She started working at All Animal Pet Hospital in May of 2019 and absolutely loves it. The animal, the clients, and her coworkers, of course, Her favorite thin about working here is the variety of animals that can walk through the front door. Until she moved to South Dakota, she had no idea people could live with raccoons and squirrels! Mandy herself has to many cats to count, and adoring husband, and a brand new two legged baby at home named Aurora.