Our caring and compassionate veterinary care team!

Meet the Veterinarians & Team of Chatfield Veterinary Hospital in Littleton! We’re pleased to provide exceptional vet care for your pets!

Please call us at (303) 978-9750 to speak to one of our caring veterinary staff members!

Our Doctors

Tyler Renehan, DVM - Medical Director

Dr. Tyler Renehan received his D.V.M. degree from Colorado State University in Fort Collins, CO. He has worked at several small animal general practices since his undergrad years and completed several externships at small animal hospitals – most recently at PetAid Colorado, a non-profit veterinary hospital in Denver. As an “Air Force brat,” Tyler moved around the country numerous times as a child, but settled down in his parents’ hometown of Colorado Springs when he was 8 years old. Tyler and his wife Trish have a Labrador mix named Ellie, and enjoy spending their time hiking, fishing, and exploring the local breweries.

Amanda Naturman, DVM - Medical Director

Dr. Amanda Naturman is from Chicago but went to college and veterinary school in Florida. She graduated from the University of Florida’s vet school in 2015.  After veterinary school she completed a one year small animal internship at Colorado State University.  The past two years she has been working in small animal general practice in Gainesville, FL while her husband finished veterinary school there.  In her free time she loves to hike and explore the outdoors, which is what brings her back to Colorado.  She also loves cooking, running, traveling, and spending time with her husband, Dan, and cat Ripley. 

Brittany Knotts, DVM

Dr. Brittany Knotts received her D.V.M. from Ross University School of Veterinary Medicine in 2018. Following her clinical year at the University of Florida, she’s been practicing at a small animal general practice in Jacksonville, FL. Brittany and her boyfriend TJ have two fur babies, a Chihuahua named Titan and a cat named Persephone. In her spare time, she enjoys hiking, painting/crafting, tending to her indoor jungle, and creating charcuterie boards.

Marketa O'Neal, DVM

Dr. O’Neal was born and raised in the Czech Republic. She graduated from the University of Veterinary and Pharmaceutical Sciences Brno in 2015. She has completed several externships during her studies, including one in Purdue University College of Veterinary Medicine in Indiana. She spent some time after graduation traveling the World and volunteering as a veterinarian in non-profit organizations, such as Soi Dog Foundation in Thailand. After a small animal internship at Referral Veterinary Clinic VETINO Jaggy in Prague, she moved to California. She obtained her ECFVG certificate in 2018, and ever since then has been working as an Associate Veterinarian in a small animal general practice in Ventura, California. She and her husband Tim are avid nature lovers, which is why they moved to Colorado in 2021. She enjoys hiking, camping, mountain biking, reading, and spoiling her 2 cats named Odin and Ta Moko.

Our Pet People

Heather, CVT - Tech Supervisor

Heather was born in New Jersey, but raised in Colorado. She has been in the veterinary field since 1998 when she enrolled in the Bel-Rea Veterinary Technician program and began volunteering at various practices. She became a certified veterinary technician in 2000 and received her associate’s degree in veterinary technology. Heather has experience in general practice (small animal and exotic), emergency medicine, shelter animals and specialty surgery practice. She has several pets of her own including dogs, cats, a flemish giant rabbit and chickens! You may bump into her at the dog park with her daughter, Raya and all the dogs following behind!

Jessica, Dog Trainer

Jessica joined the Chatfield team in August of 2009 after graduating from Colorado State University with a degree in Animal Science. She also has three associate degrees in Exotic Animal Training. Jessica is a certified trainer and offers puppy socialization and basic training classes here at the clinic and also offers private training classes where she can come to your home. When she is not at the clinic she spends her time with her beautiful family including two dogs and a cat!

Katelyn, CVT

Katelyn started at CVH as a receptionist but her love of animals lead her to the Bel-Rea Institute of Animal Technology. Luckily for us she chose to stay with Chatfield after graduation where she became one of our valued veterinary technicians. She has two dogs of her own, a Chihuahua named Bentley and a mixed breed named Pico. When she isn’t working, she enjoys spending time with her husband, her beautiful daughter and family four-wheeling in the mountains.

Hannah, CVT-Tech Supervisor

Hannah first came to Chatfield as an intern from Bel-Rea. After graduation we knew we couldn’t let her go! She is a true animal lover and loves spending time outdoors, especially paddle boarding and hiking with her sweet pup Bender.

Andrew, Technician

Andrew joined the Chatfield team after moving to Colorado from Cullman Alabama. He started out as a kennel assistant at his previous clinic in Alabama but eventually moved to becoming a veterinary assistant. He has studied Marine Biology at Bevill State Community College and the University of Northern Florida. Andrew moved to Colorado for the mountains and loves spending as much time in them as he can with his beloved dog Charlie.

Allie, Vet Assistant

Allie has been with the Chatfield team since 2012. She currently works as a veterinary assistant and a doggy daycare & boarding attendant. She loves country music, spending time outdoors with her dog Rocky and riding her horse Mocha!

Lauren, Vet Assistant

Lauren started working with pets at a very young age and loves all animals. Lauren has 4 dogs at home! A Papillion named Poppy, a Chihuahua named Aspen, a Border Collie named Honey, and a Cavalier King Charles named Faith. Her favorite thing to do is relax at home with her dogs and family. When she isn’t at home she is out hiking and rock climbing!

Dara, Technician

Dara is originally from Georgia, and just recently moved to Colorado! She comes from an equine background, and even went to school for equine science. She also competed with her horse for over 20 years. She spends most of her free time hiking with her Great Dane Tempe.

Our People People

Dominique, Practice Manager

Dominique was raised in Massachusetts but found her way back to Colorado in 2011. She has spent almost 10 years working with animals as they are her true passion, but she also spent 3 years as a certified makeup artist! She spends most of her free time with her son Milo, and fur babies Moose the chiweenie and Mooni the sphynx. She has been a part of our Chatfield family since 2016, and plans on continuing her education in management.


A lifelong animal lover, Marianne joined Chatfield in the fall of 2008. She had previously worked as a paralegal for several large law firms in California. Now an empty nester, she lives in Denver with her husband and PBGV (which is a dog in case anyone is wondering)! She volunteers at the Dumb Friends League, and suspects that she will soon add another four-legged friend to her family. She enjoys international travel, cooking, scrap-booking, reading, hiking, and the arts.

Theresa, Lead CSR

Theresa was born and raised in Colorado with a life-long love of animals.She joined the Chatfield team in March of 2019. Coming from a home that always had a cat or dog (or both), she now happily shares her home with her husband and son, two kitties, and a puppy. She’s had a lot of adventures and jobs in her life, but now she’s excited to go to work every day and help take care of animals!


Emily grew up in Georgia where she received a Bachelor’s in Biology. She moved to Colorado in spring of 2019 for an internship at Rocky Mountain NP and Yellowstone NP. After her internship, she came to work at Boarding and Daycare at CVH. She enjoys gardening, hiking, and camping in her free time. You might see her in the dog park with her family, including her Australian Cattle Dog Texas, and Schnoodle Shiloh.


Kate is a huge dog lover and has always had a passion for working with animals. She is patient with them and makes sure they all have a fun experience. She currently works at CVH part-time while also going to school for criminal justice.


Nancy is from Cleveland, Ohio and is a huge Browns football fan! She has always loved animals and has over 20 years of experience in the veterinary field. In her spare time, she enjoys playing the guitar, exercising horses, and spending time with her husband and kitty “Sonny Bunny”.

Our Daycare People

Cara, Supervisor

Cara came to Chatfield in April 2007 and shortly thereafter became the manager of our boarding & daycare facility. She has a great love for animals and has 6 dogs of her own. Cara enjoys spending her free time four wheeling, camping, mountain biking, snowshoeing, snowboarding (anything outdoors), and of course spending the most amount of time she can with her beautiful daughter!


Stacey has always been a huge animal lover and has three pets of her own, a Labradoodle named Porter, an Old English Bulldog named Stella Luna and a cat named Sprocket! She enjoys being outdoors riding her horse and spending time with her family!


Jen grew up in Maine and has been in Colorado for 20 years and has been working with animals for the last 15 of those 20. She especially loves dogs and enjoys being able to spend her days with them. She likes to spend her free time with her dog Summer.


Cat is a New York born and raised animal lover who followed her heart to the mountains. She has a dog named Calypso, two cats Ra and Brooklyn, and sugar gliders. In her free time, she enjoys finding new dog friendly places to hang out with Calypso.


Emily is a Colorado native, and has a professional photography degree from Colorado Mountain College Issicson School of New Media. She specializes in animal portraiture, and loves to photograph all animals big and small. In her free time she likes to spend time with family, hike, paddleboard, and compete in competitions with her tripod dog Bear!

Our Beauty People


Tabea has been a groomer at Chatfield since 2016. She has been making dogs beautiful since 2009. She has a crazy mutt of her own named Jilly Bean and two cats named Walter and Harriet. Tabea enjoys spending her free time with her two children and husband.