Case studies in two typical UK veterinary practices were undertaken to explore teamwork, including interprofessional working. Each study involved one week of whole team observation based on practice locations (reception, operating theatre), one week of shadowing six focus individuals (veterinary surgeons, veterinary nurses and administrators) and a final week consisting of semistructured interviews regarding teamwork. Errors emerged as a finding of the study. The definition of errors was inclusive, pertaining to inputs or omitted actions with potential adverse outcomes for patients, clients or the practice. The 40 identified instances could be grouped into clinical errors (dosing/drugs, surgical preparation, lack of follow-up), lost item errors, and most frequently, communication errors (records, procedures, missing face-to-face communication, mistakes within face-to-face communication). The qualitative nature of the study allowed the underlying cause of the errors to be explored. In addition to some individual mistakes, system faults were identified as a major cause of errors. Observed examples and interviews demonstrated several challenges to interprofessional teamworking which may cause errors, including: lack of time, part-time staff leading to frequent handovers, branch differences and individual veterinary surgeon work preferences. Lessons are drawn for building better veterinary teams and implications for Disciplinary Proceedings considered