Claudia grew up in Massachusetts as the fourth of five children. She professed to her parents at the age of five that she wanted to be a veterinarian and spent her childhood years riding and caring for horses. She showed hunters and jumpers as a teenager and worked for a large equine show jumping barn. Claudia attended Tufts University as an undergraduate. where she competed regularly in the Intercollegiate Equestrian circuit while enrolled in the pre-med program. Claudia was accepted into UC Davis Veterinary School in 1990 and graduated after completing the equine track in 1995.

Dr. Sonder has a long history with this vet clinic, both as an associate veterinarian and as previous owner. She is happy to be back in the saddle as an owner-partner at Napa Valley Equine. Dr. Sonder has a special interest in diagnosing and treating lameness in sport horses, utilizing the latest in digital imaging and joint injection procedures. She also enjoys equine neonatal medicine and assisted reproduction. In her "spare" time Claudia enjoys spending time outdoors with her three children, Molly, Mason and Merren.