Our caring and compassionate veterinary care team!

Meet the Veterinarians & Team of All Creatures Veterinary Service in Big Timber! We’re pleased to provide exceptional vet care for your pets!

Please call us at (406) 932-4324 to speak to one of our caring veterinary staff members!

Dr. Kirk Johnston, DVM

Veterinarian/Practice Owner

Dr. Johnston started his career at All Creatures Veterinary Service after graduating from Washington State University College of Veterinary Medicine in 1993. He has been a co-owner of the clinic for over 20 years and enjoys mixed animal practice in our rural community. Dr. Johnston and his wife, Elizabeth, have two daughters, Jessica and Darby, and a son, Nolan, who are finishing their high school and college educations.

Dr. Johnston was born and raised in White Sulphur Springs, Montana. He attended Montana State University-Bozeman to fulfill pre-veterinary requirements.

Kirk appreciates many outdoor recreational activities that Montana has to offer including hunting and fishing, horseback riding, and camping with his family. He and his family have many pets and have raised horses for several years.

Dr. Jason Hasbrook, DVM

Veterinarian/Practice Owner

Dr. Hasbrook grew up in Big Timber. He graduated with his DVM from Washington State University in 1998. He practiced as a mixed animal vet in Buffalo, WY and Absarokee, MT prior to returning to ACVS in 2002. Shortly after returning, he became partners in ownership of ACVS.

Dr. Hasbrook enjoys downhill skiing, so much so he has been skiing every month for the last two years! He also enjoys spending time with his wife, Heather, and his two sons, John and James. He stays busy watching his sons play sports.

Dr. Jeannine Peterson, DVM

Associate Veterinarian

Dr. Peterson joined All Creatures Veterinary Service in June 2018, shortly after receiving her Doctor of Veterinary Medicine degree from Colorado State University. She attended Montana State University-Bozeman where she received her Bachelor of Science in Cell Biology and Neuroscience in 2012. Her experience in Bozeman made her want to return to Montana and practice rural veterinary medicine.

Dr. Peterson is from the small town of Tenino, Washington. She grew up on a small farm which played a large role in her becoming a veterinarian. She has three dogs at home named Greta, Sage, and Josie.

In her free time she enjoys spending time with her husband. She also enjoys running, hiking, fishing, and hunting, especially upland game with her German Shorthaired Pointer, Greta.

Deborah Silverstein

Office Manager/Receptionist

Deb was raised in Michigan enjoying a semi-rural childhood. She spent her post-school years learning her craft of office work in some mid-western cities, including an office manager position while working for Randy Travis in Nashville. She met her husband Mark in 1992 and have lived on ranches ever since. She and Mark moved to the Big Timber area in 1999 and began working at All Creatures Vet Clinic in 2004. After enjoying this job for 13 years, she retired to spend more time on the ranch….or so she thought. After a year and a half, she returned to the clinic on a part-time basis, thoroughly enjoying being part of the All Creatures family once again.

Amanda Dunwald


Amanda joined ACVS as our receptionist in April 2022.

Connie Weston


Connie is originally from College Station, Texas and moved to Montana in October of 2015. She joined our staff as a part-time employee in August of 2016. Connie has a degree in Agricultural Education and worked as an ag chemical sales representative for 22 years. Her favorite part of the job is supporting the staff and interacting with the patients and clients.

In her spare time, Connie enjoys spending time with her husband, Jeff and their friends. They have three boxers, Mia, Rose and Ollie. She also enjoys the outdoors, cooking and reading.

Katie Jones


Katie is originally  from an Ag community in Northern California. Katie moved to Big Timber in 2018. She joined our staff as a part time employee in the fall of 2021. Katie has a degree in Agriculture Business and spent over 10 years working in accounting for a fertilizer chemical company and continues to have involvement with her families prune ranch.

In her spare time, Katie enjoys spending time with her husband and two children fishing, camping, crafting and cooking!


Katie Kepford

Veterinary Assistant

Katie Joined ACVS in September 2016. Katie was born and raised on a farm in Iowa where her family farmed corn and soybeans and raised cattle and Newfoundland dogs. Katie was heavily involved in sports growing up which fueled her to obtain her Bachelor of Arts degree in Physical Education with a coaching endorsement. 

Katie has a passion for working with youth and with animals, especially horses. This passion brought her to Montana as the head wrangler for Clydehurst Christian Ranch up the Boulder River. After spending the summer at the ranch, she found her place at ACVS as a veterinary assistant. 

In her free time, she loves to hike, backpack, ride her horse (Summer), and hang out with her dog, Layla AKA Bag of Bones. 

Jessie Dulin

Veterinary Assistant

Jessie joined ACVS in September 2019 as a veterinary assistant. She grew up on her family ranch in Malta, where her family raised and trained horses. Growing up on a ranch fueled her passion for animals, especially her love for horses. She is a very compassionate, kind-hearted, and driven person. 

Jessie is happy working in the veterinary industry once again. She enjoys helping all four-legged creatures and their owners. Jessie has been head veterinary assistant at Livingston Veterinary Hospital, an equine manager and trainer at Circle T Ranch, and has worked locally at the Frosty Freeze. 

Jessie and her family have 5 horses (Misty, Ginny, Chrome, Jellybean, and Mayzie), two German Shorthaired Pointers (Pidge and Ringo), and one cat (Chomper). She enjoys spending time with her four-legged friends, barrel racing, fishing, and hunting. Most of all, she enjoys spending time with her husband and daughter. 

Madelyne Stewart

Veterinary Assistant

Madelyn joined ACVS in October of 2017. She was born and raised in upstate New York, on her great-granddad’s Hereford farm. She grew up with horses on the farm and found a great love and appreciation for them.

Madelyne achieved a bachelor’s degree in equine business management with a certification in equine reproduction. She recently received certification in equine breeding and foaling through the Kentucky Equine Management Program. She is working towards a Veterinary Technician License.

Her passion for horses and the West brought her to Montana as wrangler at Hawley Mountain Guest Ranch. Since 2017 she has spent her summers up the mountain at the guest ranch and spends the rest of the year with us here at ACVS.

In her free time she enjoys hiking in the mountains, riding her horses, and continuing to learn.