About Us

Why choose us?

The Pet Doctor was founded in 2005 and has provided quality care for O’Fallon and the surrounding communities ever since. Our practice is also St. Charles County’s only American Animal Hospital Association (AAHA)- accredited hospital. Simply put, our mission is to provide the very best care for your best friend. We hope you spend a few minutes browsing our website to learn about our practice, or better yet, come in to see it for yourself. We can’t wait to meet you and your pet!

Get to know us!

Marcy Hammerle, DVM

Dr. Hammerle's Bio
Fear-Free Certified

Hi! I’m Marcy Hammerle, DVM. I am a 2003 graduate of the University of Missouri College of Veterinary Medicine. I grew up in St. Charles, MO and still live there with my husband, Tom Coletti, and our 3 children, Cassidy, Michael and Audrey. I always had a love for animals and the dream of becoming a veterinarian. I was lucky to grow up in a family that indulged my passion and surrounded me with pets. We currently are the proud owners of 3 dogs, 2 cats, 2 horses, 8 chickens, 4 bunnies and 2 hermit crabs, so as you can imagine, our days are very full.

I am very proud to be a part of The Pet Doctor. We do our very best to provide excellent medical care for your pets. We strive to be the best that we can, from our AAHA hospital accreditation to our commitment to continuing education. Everyone on our staff has a strong passion for our profession and a love for animals. I feel lucky to be surrounded by such a great group of people every day!

In 2011, I worked hard to achieve the status of a Diplomate of the American Board of Veterinary Practitioners as a Specialist in canine and feline medicine.  This was a very important goal for me.  The ABVP describes their accreditation in the following way:

This information is from www.abvp.com:

The answer is in the depth of knowledge and competency in their field and the level of veterinary service the board-certified veterinarians are able to provide and the fact that they have demonstrated this by completing the certification process by a recognized specialty organization.

The ABVP board certified veterinarian has demonstrated by the certification process that they are capable of providing a level of clinical practice that is clearly superior to the norm of the profession. It is the goal of the ABVP that practitioners who excel in the art and science of clinical practice would seek certification.”

At The Pet Doctor, we are proud to provide this level of care for our patients and we will continue to work hard to stay at the top of our profession.


*GSLVMA Vice President, 2015-2016
*Missouri Veterinary Medical Foundation Board
*AVMA member since 2003
*MVMA member since 2003
*AAHA member/credentialed hospital since 2005
*AVMA Leadership Conference 2005
*AAH-ABV (American Association of Human Animal Bond Veterinarians) board member
*MVMA Veterinary Technician and Practice Staff Committee Chair

*MVMA New Graduate task force member
*MVMA conference speaker
*AVMA CVTEA credentialing committee for Hickey College

*AVMA member since 2003
*MVMA member since 2003
*AAHA member/credentialed hospital since 2005
*AVMA Leadership Conference 2005
*AAH-ABV (American Association of Human Animal Bond Veterinarians) board member
*MVMA Veterinary Technician and Practice Staff Committee Chair
*Missouri Volunteer Veterinary Corps member
*MVMA New Graduate task force member
*MVMA conference speaker
*AVMA CVTEA credentialing committee for Hickey College

Awards & Achievements

*2008 St. Louis Best Veterinarian (St. Louie Tails Magazine)
*2009 St. Louis Best Veterinarian (St. Louie Tails Magazine)
*2010 St. Louis Magazine “5 Star Veterinarian

Laura McManus, DVM

Dr. McManus' Bio
Fear-Free Certified

I have lived my whole life in the Saint Louis area. I attended Incarnate Word Academy for high school and then headed off to Mizzou. I spent 2002-2006 earning my bachelors degree in Biology before continuing to The University of Missouri College of Veterinary Medicine from 2006-2010. My first 7 years were spent learning clinical and surgical skills in a small animal practice in Chesterfield. My interests include surgery, ultrasound, and internal medicine.

I met my husband in grade school. We began dating sophomore year of high school and have been together ever since. We have been blessed with a marriage of 9 years and 18-month-old triplets who keep our lives very busy! Our household is rounded out by a 10-year-old Australian Shepherd named Brewer.

Kate Callaway, DVM

Dr. Callaway's Bio
Fear-Free Certified

Hi! I’m Kate Callaway, DVM. I graduated from the University of Missouri College of Veterinary Medicine in 2009. I am originally from Kansas City, but moved to St. Peters with my husband, Kyle, after graduation. Together we have two kids, Declan and Teagan, as well as two dogs, Dublin and Kimbo. I knew at a young age I wanted to be a veterinarian. My parents were very encouraging, even when that meant stopping the car for the hundredth time so I could move another turtle out of the road.

After graduation, I practiced emergency medicine for 4 years before switching focus to small animal general practice and I am very excited to now be a part of The Pet Doctor! I truly enjoy building relationships with clients and their animals. I have a special interest in emergency and critical care medicine as well as diagnostic imaging. I am a member of the American Veterinary Medical Association, the Missouri Veterinary Medical Association, and the Greater St. Louis Veterinary Association.

Shannon Broyles, DVM

Dr. Broyles' Bio
Dr. Broyles joined The Pet Doctor staff in 2015, and she already enjoys working with our staff and interacting with owners and their beloved pets. She is a 2000 graduate of the University of Missouri College of Veterinary Medicine and is a member of the American Veterinary Medical Association, the Missouri Veterinary Medical Association and the Greater St. Louis Veterinary Medical Association.

Dr. Broyles shares her home with two dogs, two cats, and eight chickens. Llewellyn is a 5-year-old Labrador Retriever, Matilda is a 1-year-old Golden Retriever, Hemingway is a 3-year-old grey/white tabby and Kevin is an 8-year-old brown/black tabby. Maude, Mavis, Sandra, History, Static, Charlotte, Joyce, and Violet are her 1 1/2-year-old chickens.

In her free time, Dr. Broyles loves spending time with her 3 children: ages 11,9 & 6. They enjoy camping, biking, canoeing, hiking, rock climbing and skiing as a family. She also likes scrapbooking, sewing, crafting, and underwater basketweaving. She volunteers for her school and church, is a troop leader for two girl scout troops and as a veterinarian for the World Bird Sanctuary. she feels a balance of work and family is the key to happiness.

Terry Surtin, DC

Dr. Surtin's Bio
Doctor Surtin has witnessed the wonderful changes that his service brings to his human patients. Approximately three years ago, he experienced an unfortunate experience with his pet. He saw the need for the healing art of chiropractic with animals -large and small. Doctor Surtins’ goal in providing chiropractic care for your animal is to locate and give treatment to the part of the spine and skeletal system which is causing inflexibility and pain. We provide detection and treatment of spinal nerve and musculo skeletal problems which cause: pain, limping, immobility, appetite loss, lethargy, and hiding.

Animals, like humans, can have headaches, jaw pain, mid and lower back pain, constipation, and problems with their limbs.

Jessica, Vet Technician & Office Manager

Jessica's Bio
Fear-Free Certified

Jessica joined The Pet Doctor team in 2006. She currently serves as a veterinary technician and also the office manager. Her hard work and dedication to the practice led her to be named to the Missouri Veterinary Medical Foundation’s Veterinary Practice Staff Honor Roll in 2015. You can read more about Jessica’s Honor Roll award here.

Jessica shares her home with Dorie, a Boston terrier who was “created” at The Pet Doctor years ago! Her mom was artificially inseminated and had a C-section at The Pet Doctor, and is now a part of the family! When not at work, Jessie enjoys playing softball, going camping, float trips and taking care of wildlife.

Tiffany, RVT

Tiffany's Bio
Fear-Free Certified

Tiffany joined The Pet Doctor family in 2009 after completing her RVT training at Sanford Brown.

When asked about her favorite part of the job, Tiffany said: “My favorite part of the job is helping the patients and being able to see them recover. I really enjoy being there for our clients also! I feel like they know we will always be there for them.”

Tiffany shares her home with Dunkin, an 8-year-old rescued Golden Retriever and Suge Knight, a rescued English bulldog.

In her free time, Tiffany enjoys outdoor activities like hiking, walking her dogs and gardening.

Joni, Veterinary Technician

Joni's Bio
Fear-Free Certified

Joni has been a part of The Pet Doctor family since 2006. She holds a BA in Art from Webster University, a BS in Human Biology from Logan College of Chiropractic and a BS in Occupational Science from St. Louis University.

When asked about her favorite part of the job, Joni said: “I love being able to build relationships with the clients and their pets. And I love working with rescue! My job challenges me in some way every day and I don’t think I could ever have a job that didn’t challenge me.”
Joni shares her home with several pets:

  • Remington, a 9-year-old mastiff from The Pet Doctor to the Rescue
  • Boris, a 5-year-old pitbull mix (who came as a puppy for a Mother’s Day present!)
  • Arlo Guthrie, a 3-year-old mastiff mix who was born at the clinic
  • Amos, a 4-year-old mastiff mix from The Pet Doctor to the Rescue (and her favorite!)
  • Cecil Peoples, a DSH who was found in a live trap near her house
  • Sgt. Rourke, a DSH
  • Reggie, a groundhog who came as a baby from wildlife rescue but now lives on her property
  • Gilda Radner, a cow, who was a bottle calf. At five months old she is already a “mean hussy!”

In her spare time, Joni enjoys hiking, working in her garden, rock climbing and rolling around with her dogs.

Melissa, RVT

Melissa's Bio
Fear-Free Certified

Melissa joined The Pet Doctor staff in 2009 and holds an Associate of Applied Science from The Vet Tech Institute at Hickey College.
When asked about her favorite part of the job, Melissa said: “The awesome team I work with! They make even the hardest day more fun! I also love talking to all our awesome clients and educating people about new products and services we offer!”

Melissa shares her home with several pets:

  • Charley, a 9-year-old chocolate lab who loves to fetch anything
  • Chloe, a 13-year-old border collie mix (her sweet old girl!)
  • Fritz, a 7-year-old beagle mix who is the best dog with little kids
  • Harry Elephante, a 2-year-old hairless Chinese Crested/French bulldog mix

In her free time, Melissa runs a small business with her sister, S&P Handmade Happiness, making all natural beauty products and unique tie-dyed items.


Annie's Bio
Fear-Free Certified

Bio coming soon.

Brook, RVT

Brook's Bio
Bio coming soon.

Amy - Receptionist

Amy's Bio
Bio coming soon.

Dave, Facility Maintenance

Dave's Bio
Bio coming soon.


Dominique's Bio
Bio coming soon.


Angie's Bio
Bio coming soon.

Paul, Office Cat

Paul's Bio
Bio coming soon.