This is a team of passionate animal lovers who truly love what we do. We don’t come in to work to earn a paycheck. We come into work to change and save lives. Now, get to know us.


Cassi K. Pettyjohn, B.S., D.V.M.

Veterinarian/Practice Owner

Dr. Cassi Pettyjohn grew up in a small town in Southwest Kansas. She graduated from Kansas State University in 2002 with a bachelor’s degree in animal science and in 2006 with a Doctor of Veterinary Medicine degree from Kansas State University College of Veterinary Medicine.

After graduation, Dr. Pettyjohn pursued a career in equine medicine, which took her to the great states of Iowa, Virginia, and Texas. After moving to the Houston area, Dr. Pettyjohn began to specialize in small animal medicine. Her special interests include dermatology, internal medicine, and dentistry.

She is married with 2 children, two miniature Australian Shepherds (Ankiel and Molina), one cat (Pudge) —all her animals are named after Major League Baseball Players. She enjoys spending time with her family and helping her husband around the farm.

Mandy Hall


Dr. Hall is ecstatic to call Stone Ridge her second home. After taking off a year to explore her interests in public health, she has happily returned to the Stone Ridge family.

Dr. Hall’s areas of interest are soft tissue surgery (including high quality, high volume spay and neuter), dentistry, internal medicine, and neurology. Her favorite aspect of veterinary medicine is being able to educate the public on caring for their pets to give them a long and healthy life.

When she is not at work, Dr. Hall can be found spending time with her husband and their two fur-children: Bruce and Perry.

“When I look into the eyes of an animal, I do not see an animal. I see a living being. I see a friend. I feel a soul.”

-AD Williams

Care Team

Mandy Spence, B.S.

Practice Manager

Mandy graduated from California State Polytechnic University, Pomona, with a bachelor’s degree in biology in 1994. After graduating from college, she moved back to her childhood home in Willis.

She currently lives in the Woodlands with her husband and pets, which include dogs, cats, and birds.


Veterinary Technician

Holly was brought up in Palestine Texas. Moved all around Texas, including Abilene, but eventually settled in Willis Texas. Holly recently completed her Bachelors in Animal Science at Sam Houston with a minor in Wildlife Management. She is married with three children who take up all of her extra time. Holly and her family also have a German Shepherd mix rescue named Kiera, a white boxer named Lacey, and a blue Quaker named Maize. She has a passion for animals since she was a little girl. She remembers playing vet with her Beanie Babies. When she was living in Abilene, she volunteered at the Abilene Zoo, which ignited her interest in exotic animals, including snakes. From there, she decided to pursue my degree. She loves all animals and is excited to provide love and care for them. If she were to have a side hobby, she would enjoy music and singing. She used to be a part of a praise and worship team at a church in Abilene. She also loves the outdoors whether hiking, fishing, shooting, or horseback riding.


Licensed Veterinary Technician

Born and raised in The Woodlands, Texas; I am a licensed veterinary technician. I graduated from LSC-Tomball with an Associates in Applied Science and a Veterinary Technology degree in 2011. I then got my Bachelors in Wildlife and Fisheries with an emphasis in Vertebrate Zoology from Texas A & M University in 2014. I love working with most exotics, but birds are my ultimate favorite! My passion in veterinary medicine is dentistry as well as client education; but all aspects of this field are fascinating and intriguing. I have three dogs, Wrangler, Cinch, and Keena; three cats named Quill, Groot and Dory; one horse named Red, and two quakers, Gunny and General.


Veterinary Technician

My name is Christy DuVall and I have been married for over 25 years to my husband, Jason. We have a daughter, Taylor and her husband Ryan who live in north Fort Worth. We are empty nesters who have a Boston named Durham, a dachshund mix named Beltre, two cats Stitch and Creed, and a few fish pets. I have been a Veterinary Technician since 1999.

Brenda, B.F.A.

Client Care Specialist

I was born and raised in a small Texas town. I attended Sam Houston State University where I earned a degree in Mass Communication. I am lucky to be in a profession that allows me to pursue an array of areas: animal advocacy, client relations, and social media management being my favorites.

Outside of work, I enjoy cooking and baking, tackling Pinterest projects, and celebrating all of the holidays. I currently reside in Huntsville with my college sweetheart husband, our spoiled rescue Doodle-mix Goldie, and our rotten felines, Duke and Eloise.


Client Care Specialist

Paige was born in The Woodlands but raised in Willis, Texas. She is currently attending school at Lone Star Community College. She has always had a special place in her heart for animals since she was a toddler. She has one dog, Ace, and two horses that she loves very much. In her free time she’s usually in the arena with her horses or out on Lake Conroe.


Veterinary Technician

I grew up in Spring, Texas for most of my life and slowly made my way up to the Huntsville area. I am currently a student at Sam Houston State University aiming for a bachelors degree in Animal Sciences and a minor in Equine Sciences. I have always enjoyed being in the presence of animals and strive to be apart of the change to make veterinary medicine better each and every day.


Licensed Veterinary Technician

Rhonda grew up on a farm in South Dakota where she learned she loved veterinary medicine. An accomplished barrel racer, she helped the local veterinarian to pay for her horses. She always loved animals and hand raised a fawn, several orphaned raccoons, bunnies and even a couple of foxes. She attended school in Arizona, and in 1989 she became a licensed technician. In 1995, she moved to San Antonio. Wanting to leave the city, she came to Stone Ridge in June of 2020. She has a special interest in feline medicine and behavior and uses a fear free approach. During her off time she is an advocate for wild mustangs, likes to hike, zipline and skydive.


Client Care Specialist

Lacey was born in Houston, Tx but was raised in Willis, Tx. She is married, has three children, and four dogs. Lacey decided to buy a house in New Waverly where she enjoys spending time with her kids and extended family.


Licensed Veterinary Technician

My name is Aubrey. I was born and raised here in Houston, Texas. I’ve been an animal lover since I was a child. I have a 10 year old daughter who loves animals almost as much as I do. I have 3 dogs (Riley, Max, & Sugar) and 3 cats (Tigger, KiKi, and Toby). I was in college & became a Nursing Assistant (for humans) in 2012 & worked at a Neurorecovery center for 4 years. I decided after that to pursue my ultimate passion of working with animals and went back to school to obtain my Associate of Applied Science in Veterinary Medicine. I recently passed the Texas State Board Exam to become a Licensed Veterinary Technician. I have major interests in anything neuro, but also exotics! Outside of work I enjoy games, watching cartoons, spending time with family and friends.


Veterinary Assistant

Leslie was born in Conroe and raised in Willis. He is currently a SHSU student majoring in Political Science. Soon after joining the Stone Ridge team, he foster-failed an orange kitten named Mr. Krabs. Aside from being a cat-dad, Leslie enjoys cooking and testing new recipes as well as discovering new music.


Veterinary Assistant

I am a Texas native. In high school, I was involved in FFA: I showed steer and pigs and participated in livestock judging. I am excited to start a career centered around helping (and cuddling) all the animals. I am currently a “CCS,” but I’m also training to be a technician assistant.

I currently reside in Willis with my high school sweetheart and a rescue feline, June Bug (Bug). My dream is to live on a farm with lots of farm animals and dogs.


Goodwill Ambassador

Push is our resident cat. He came to us as an orphaned kitten in 2013. One of our clients found him on a golf course with a seemingly broken leg. During his exam, he persistently “pushed” the technicians’ hands for optimum pets and scratches, earning him his name.

Push’s road to recovery started off bumpy with the possibly of a leg amputation in his future. The technicians and veterinarians nursed Push back to health, and his broken leg healed on its own- perks of being a strong, feisty kitten!

If he’s not napping in his cat tower, Push loves begging for dog jerky treats, greets clients and patients, and loves to investigate carriers as well as oversized handbags.


Veterinary Technician

Bio is Coming Soon!


Veterinary Assistant

Bio is Coming Soon!


Veterinary Assistant

Bio is Coming Soon!