Contemporary felinology is undergoing an intensive transformation, one of the key manifestations of which is the growing interest in the breeding of hybrid cat breeds that combine a pronounced exotic wild-type phenotype with behavioural characteristics acceptable for household companion animals. The focus of the present study is the Caracat breed, an interspecific hybrid of the caracal and the domestic cat. Despite the substantial commercial success and considerable popularity of these animals, questions concerning their welfare, particularly with regard to the early hybrid generations (F1–F2), remain an area of intense scientific and ethical debate. The stress assessment metrics adopted in clinical and research practice, such as the Cat Stress Score (CSS), which were developed for domestic cats, prove to be insufficiently informative and sensitive when working with hybrid forms whose ethological and physiological profiles deviate substantially from those of Felis catus. This paper presents the development and empirical validation of a new Hybrid Feline Welfare Index (HFWI), conceptually based on the updated Five Domains model. The empirical basis of the study was formed from a unique body of observations collected in the VIPLEO cattery, which currently occupies a leading position in the global practice of Caracat breeding and was the first to obtain fertile males of the fifth generation (F5). The sample includes data obtained under stationary housing conditions (Kyiv, Ukraine), in the extreme context of evacuating animals from an area of active hostilities (2022) and their subsequent adaptation in the USA (Florida), as well as the results of an analysis of show activity within the frameworks of TICA and CFC Sofi systems. Statistically significant differences in the adaptive potential of animals of generations F1 and F5 are demonstrated, which empirically supports the initial hypothesis that targeted selection up to the fifth generation can substantially mitigate most welfare risks characteristic of early hybrids. On the basis of the obtained data, practical recommendations are formulated concerning housing conditions, dietary features and ethical principles for exhibiting hybrid cats, and the need for a differentiated approach to the legislative regulation of this segment of felinological practice is substantiated. The paper will be of interest to felinologists and specialists in the breeding of hybrid cat breeds, veterinarians and ethologists, animal welfare experts, as well as specialised felinological and regulatory organisations engaged in discussions on the ethics of housing and breeding hybrids.