Simple SummaryThe issuing of expert opinions is rarely found as a topic of discussion in veterinary colleges as one of the forms of veterinary practice. At the same time, it has a significant social, legal, and economic impact. This article examines veterinary experts and expertise from an interdisciplinary ethical and comparative legal perspective, regarding different definitions and underlying basic assumptions concerning the meaning of veterinary expertise. Analysis reveals how the terminology used changes the perception of the examined institution. Legally relevant factors of an expert opinion are identified: direct connection with the law and the intended, applied use of this opinion in a legal context. A variety of sources of legal and ethical duties and the related liability of the veterinary expert are revealed, both as a proficient and as a member of a public trust profession. Different theoretical and practical suggestions are made to clarify and facilitate expertise in various contexts of veterinary professional practice.AbstractVeterinary professional practice can be performed in many forms, including expert activity. The importance of veterinary expertise is, however, often underrated and limited to only one of its areas. Nonetheless, veterinary expert opinions have significant social, legal, and economic impacts. This study investigates veterinary expertise from an interdisciplinary, comparative perspective. Ethical and legal analysis and interpretation are performed. Essential concepts and relevant aspects of veterinary expertise are analysed. Legally relevant factors of an expert opinion are identified. The relationship between the law, the language, and the understanding of the role and duties of a veterinary proficient is demonstrated. A variety of possible expert opinions and the multiplicity of veterinary scopes of such activity is presented. It is argued that the ranges of forensic veterinary medicine and of veterinary expertise are broader than is predominantly assumed. Veterinary forensic medicine is a crucial part of veterinary specialisation. Ethical and legal basics, and the scope of veterinary expert’s liability, are revealed and discussed. The conclusion is that the duties and responsibilities of expert veterinarians are particularly great due to the exercise of the public trust profession, with large importance for the whole society. Their observance is, however, crucial to ensure the highest quality of expert opinions issued by veterinarians.