Our Doctors

Dr. Anita Knudson


Dr. Knudson completed her undergraduate work at SUNY at Stonybrook in New York. She received her veterinary degree from Colorado State University Veterinary School in 1993. She has worked in the Boulder-Longmont area since graduation. Dr Knudson opened Coal Ridge Animal Hospital on October 1, 2001. In addition to practicing small animal medicine she enjoys volunteering in the local community. She has set up a program to assist the local municipalities with the feral cat population and provide care for the local police dogs.

Dr. Deb Lanzi

Dr. Deb Lanzi was born and raised in Maryland, moving to Colorado in 2000. She completed her undergraduate degree at the University of Colorado at Boulder in 2004, with a double major in Kinesiology and Applied Physiology and Environmental Biology. After working in various areas of human health and fitness, she completed a dual degree at Colorado State University, earning her Masters of Business Administration (2014) and Doctorate of Veterinary Medicine (2017). Dr. Lanzi joins the Coal Ridge team as a new doctor and is excited to see where this new career will take her.

Dr. Hallie Sloan 


Dr. Hallie Sloan, originally from Texas, moved to Colorado to pursue her formal education in 2008. She graduated from Colorado State University in 2012 with a Bachelor of Science in both Biology and Zoology, and then a Master of Science in Biomedical Sciences in 2013. In 2017, Dr. Sloan completed her DVM in Veterinary Medicine from CSU and started her career as a small animal practitioner. She loves witnessing first-hand the human-pet bond, and is thrilled to do her part in keeping it strong and healthy. Outside of veterinary medicine, you can find her spending time with her family and doing all the wonderful outdoor activities that Colorado has to offer. She also enjoys those lazy days watching movies and cross stitching with a happy cat in her lap.

Dr. Erica Thiel


Dr. Erica Thiel joined Coal Ridge Animal Hospital in June 2018 as an associate veterinarian. She was born and raised in Nebraska, moving to Colorado in 2018. She completed her undergraduate degree at Nebraska Wesleyan University in 2010, earning a Bachelor of Science in Biology. She graduated from veterinary school at Iowa State University in 2014 and has been working in the small animal field since. Her interests include internal medicine, dermatology, and dentistry. She is excited to have joined the Coal Ridge team and meet all our wonderful clients and patients.


AAHA American Animal Hospital Association
ABKA American Boarding Kennels Association
ARAV Association of Reptilian and Amphibian Veterinarians
AVMA American Veterinary Medical Association
CVMA Colorado Veterinary Medical Association
LPVMA Longs Peak Veterinary Medical Association

Our Values Statements

  • Quality Pet Care
  • Community-Friendly Hospital
  • Friendly & Informative Staff
  • We Treat All Animals Like Our Own
  • Comfortable and Spacious Boarding Facilities