Our Doctors


Medical Director

Dr. Matt Duff was born and raised in Minneapolis, Minnesota. He obtained his undergraduate degree in phycology at Mankato State University in Southern Minnesota. He then went on to begin his veterinary education at the University of Minnesota and graduated in 2007. Dr. Duff worked General Practice in Minnesota and joined Rockford Road Animal Hospital in 2012. He promoted to Medical Director in 2017, and was transferred to Houston in 2021. He is now our new Medical Director at All Pets Animal Hospital in the General Practice department.


Dr. Duff enjoys the bond he has with his clients while providing exceptional care to your beloved pets. He enjoys dentistry along with building a bond with his staff and the community.

In his down time, he enjoys flying radio-controlled airplanes, tinkering with his jeep, shooting sports, cooking, and spending time with his daughters.



Dr. Jaclyn Zangre was born and raised on Long Island, New York. She began her veterinary education at the University of Connecticut where she earned a Bachelor’s degree in Animal Science, which she followed with earning her Doctorate of Veterinary Medicine from the University of Missouri.  Dr. Zangre moved to Katy immediately after graduation, for the opportunity to work at such a fast-paced and multi-faceted practice as All Pets Animal Hospital, and has been a member of the team ever since.


As Dr. Zangre has an affinity for Emergency and Critical Care and diagnostic imaging, you’ll likely find her working All Pets’ emergency cases overnight. She enjoys the pressure of the emergency environment as well as the opportunity to practice a broad scope of veterinary medicine. Outside of work, Dr. Zangre is a human mom, dog mom, and fitness enthusiast, and can either be found chasing her toddler, chasing her beagle, or relaxing at the gym.

As she jokes with her emergency clients, she hopes not to have to see you after hours, but please know, we are always here for you! She and her team of emergency technicians strive to provide excellent care to their patients and peace of mind to their patient’s owners, treating each pet like they would their own.


Associate Veterinarian

Dr. Choyce chose veterinary medicine because he has always been fascinated by animals and their relationship to people, and he genuinely enjoys helping others.  After being in veterinary 4H classes and working for a veterinarian in high school, he found his passion.


Dr. Patrick Choyce is a 1983 graduate of the Texas A&M University College of Veterinary Medicine. He also completed his undergraduate studies at Texas A&M in Animal Science. Upon graduation, Dr. Choyce practiced for three years as an associate in small and large animal practices before moving into emergency medicine. After practicing for 5 years in emergency practice and daytime relief practices, Dr. Choyce opened All Pets Animal Hospital on Mason road in March 1990. After 21 years, he moved the practice to the current location and new modern facility on Kingsland Boulevard.  The new building was named one of the top ten practices for facility design in 2012. 

View our Facility Award 

Dr. Choyce’s favorite part of his job is helping animals by treating and preventing disease.  He feels extremely privileged to be able to help enhance the bond between animals and their owners.  He also loves to help team members grow and succeed as veterinary health professionals. 

Although his family is from Houston his dad was a naval aviator, so Dr. Choyce grew up all over the United States. Besides enjoying veterinary medicine as his profession, Dr. Choyce enjoys spending time with his wife Dodie, children, grandchildren, and extended family. The Choyce’s pet family includes two Tuxedo short hair cats “Groucho” and “Faustina” and goldendoodle dog “Clare”. He also cares for foster and rescue dogs, birds, and cats which he has taken in to provide homes. Dr. Choyce also enjoys working out, camping, backpacking, playing guitar, singing, studying Spanish, participating in youth and mission activities at church, and volunteering for service work to several organizations.

Dr. Choyce’s Social Media: 

Linked In Profile: https://www.linkedin.com/in/patrick-choyce 



Certified Canine Rehabilitation Therapist (CCRT)  and Certified Veterinary Acupuncture Therapist (CVAT) with the Canine Rehabilitation Institute (caninerehabinstitute.com)  

Accredited Hospital with American Animal Hospital Association for 25 years 

Recover Initiative Trained in Basic and Advanced Life Support by Veterinary Emergency and Critical Care Society 

Fear Free Level 3 Certified Veterinarian 

Cat Friendly Gold Level Practice 

FASTVet trained in ultrasound 

Sound Technology Trained in Abdominal Ultrasound and Echocardiograph 

PennHip certified to evaluate for canine hip dysplasia 

Trained in Arthrex Veterinary Tightrope Method of Canine Cruciate Ligament Repair 

Active Memberships: 

Harris County VMA
Texas VMA 

American VMA
American Animal Hospital Association
Veterinary Hospital Managers Association 

Veterinary Study Groups
Veterinary and Emergency Critical Care Society
American Academy of Feline Practitioners
North American Pet Pig Association
Association of Avian Veterinarians
Association of Reptile and Amphibian Veterinarians
Association of Exotic Mammal Veterinarians
Bunny Buddies
House Rabbit Society
Member with A+ Rating and Award for Excellence, Greater Houston Better Business Bureau
Member, Greater Katy Area Chamber of Commerce 



Dr. Manning attended the Ross University School of Veterinary Medicine and graduated in 2020.  She is a Fear Free Certified Professional.

Dr. Manning chose veterinary medicine because she loves animals and providing treatment, care, and ensuring the well being of her patients is her greatest joy! Her favorite part of her job is the endless reward she gets from discharging happy, healthy patients back to loving owners. She lives for the moments when sick patients turn into healthy smiles and happy tail wags.


Dr. Manning has three fur babies of her own, two chocolate labs and an island kitty.

You can see Dr. Manning on the Inpatient/ER team, standing by, ready to help your babies in emergencies.



Dr. Zhang is a proud graduate from the University of Florida and received both her undergraduate and veterinary degrees as a proud Gator! She decided to become a veterinarian because she wants to be a promoter of empathy through education and leadership. The human animal bond is particularly important to Dr. Zhang, and she embraces the role of being the community’s trusted ambassador for animal health and wellness.


She is a child of immigrants and is a first-generation student in the United States. She chose Katy because it offers close suburban living while still being close to a major city. Diversity in food and activities is important to her. In her free time Dr. Zhang enjoys weightlifting and searches out random adventurous experiences. She lives with her bull terrier, Jemini and holds the Guinness world record for moving the most amount of coffee beans with chopsticks in under 30 seconds!


Associate Veterinarian

Dr. Marshall is a graduate of Texas A&M University and a member of the Texas Veterinary Medicine Association and the American Veterinary Medicine Association. She has wanted to be a veterinarian since she was just a kid growing up nearby in Cypress, TX. She chose to come back to work in the Katy area so that she could be close to her family and friends.



Her favorite part of veterinary medicine is being an advocate for pets. Client education is extremely important to Dr. Marshall, and she has been complimented for her bedside manner and ability to be a team player. She has a dog, Charlie, and a bearded dragon, Echo. In her free time, she enjoys going to Astros games with her friends and she loves to bake!


Associate Veterinarian

Dr. Prudence Sun is a local, from Houston, and comes to us with a BS from Rice University and a DVM from Texas A&M University. She is a member of the American Veterinary Medical Association, the Texas Veterinary Medical Association, the American Animal Hospital Association, and the American Academy of Veterinary Dermatology. She decided to become a veterinarian because she is fascinated by the human-animal bond and is enthusiastic about helping pet owners make the best decisions for the care of their non-human children.



Dr. Sun considers earning her DVM her biggest accomplishment; and is often complimented on her thoroughness and mindfulness. Her ideal client is receptive, asks questions, and brings baked goods to share (hint, hint)! In her free time Dr. Sun likes to listen to audiobooks, take dance classes, and watch psychological thrillers. She lives with her 11-year-old hound mix, Toby, and her 13-year-old ragdoll, Peaches.



Dr. Clower was born and raised in a small suburban town outside of Fort Worth, Texas. She began her veterinary career working in vet clinics when she was 16 and her passion grew from there. She attended East Central University in Oklahoma to obtain her bachelor’s degree in biology and then Oklahoma State University where she graduated with her Doctorate of Veterinary Medicine. Dr. Clower is a member of the American Veterinary Medical Association and the Harris County Veterinary Medical Association and is Fear Free and RECOVER Certified.



After being in Oklahoma for far too long, Dr. Clower was happy to move back to her home in Texas and join All Pets in Katy. Dr. Clower enjoys Emergency Medicine and Internal Medicine, using both to help figure out the pieces of the puzzle to help best diagnose and care for your pets. She enjoys the challenge and the fast-paced environment associated with a busy practice such as All Pets. Her favorite part of being a veterinarian is being able to advocate for animals who cannot do so themselves and sending home patients feeling better to happy owners!

Outside of the hospital, Dr. Clower loves to travel the world with her husband. Her favorite place to visit is Disney World, which she visits at least once a year. Dr. Clower has three children, a Corgi named Gilligan, a GSP named Cricket, and her Betta fish, Squidward.

Kathryn Klotz, DVM

Associate Veterinarian

Dr. Klotz is a proud native Texan who was born and raised in Spring. She has always had an interest in both animals and medicine since she was very young as a result of following her mother to work to the Houston medical center, and riding horses competitively for 10 years (English style, Hunter/Jumper). She started working as a veterinary technician at an equine only clinic at 16 years old but has had numerous other jobs scattered between her veterinary experiences including pizza delivery, waitressing and even door-to-door sales! As a result, Dr. Klotz enjoys the business management side of veterinary medicine and will often go to conferences that focus on leadership, sales and communication.



She spent nearly a decade at Texas A&M University, College Station for her undergraduate degree in Biochemistry and Genetics followed immediately by her veterinary degree. While she enjoys working with dogs and cats, her fascination with dragons as a kid has turned into a passion for helping owner’s with their reptiles, birds, small mammals and any other creepy crawlies they have and love. Her goal is to one day become board certified in Reptile & Amphibian Medicine. She only has one pet at the moment; the love of her life, a 9-year-old bearded dragon named Merlin! Dr. Klotz also enjoys most any outdoor activity, learning Spanish, reading fantasy fiction and personal development books, cooking, target shooting, axe throwing and traveling all across the great state of Texas to see her friends and family on the weekends. She looks forward to getting to know both you and your pet!