The online review of veterinary services, as a new format of interaction between the client and the veterinarian, represents a value-oriented genre of veterinary discourse, characterized by variability in structure and volume. The high degree of emotionality and expressiveness indicates a strong positive bond between human and animal. This study fits into the framework of an innovative interdisciplinary approach to the concept of zooesis. The article aims to describe the linguistic means of expressing evaluation in an online review as a new genre of veterinary discourse and to determine the prospects for research. The study employed general scientific analysis methods, descriptive methods, and componential analysis. We analyzed 500 customer reviews of UK veterinary service providers posted on the clinics’ official websites. We found that the primary means of expressing evaluation is evaluative vocabulary, phraseology, and expressive syntax, while nonverbal emotional cues are used to a lesser extent. It has been demonstrated that the arbitrariness of the subject’s choice of linguistic means leads to the violation of linguistic norms which brings online veterinary reviews closer to colloquial speech. It has also been established that the majority of reviews (93%) are melioration-oriented. The linguopragmatic properties of linguistic means of expressing assessment in an online review of veterinary discourse are determined as a factor ensuring the success of distance communication, influencing the image and reputation of a veterinary institution. The results of this study can be used in university courses on communication in veterinary medicine and veterinary ethics. Prospects for future research include comparative stylistic studies of the online review genre and other genres of Internet content, and comparative analysis of online reviews.