Dynamics of skin scar formation as a subject of forensic veterinary examination

Abstract

The study examines the morphological, histological, ultrasonographic, and luminescent characteristics of skin scars in dogs and cats caused by stabbing and cutting instruments, analyzed dynamically throughout the wound healing process. It is demonstrated that skin scars possess clearly defined features that vary depending on the duration of scar tissue formation and can be used for the approximate determination of the age of injury. It was established that the process of scar formation proceeds through sequential stages of inflammation, proliferation, and remodeling, which are characterized by specific histomorphological patterns, including changes in cellular composition, organization of collagen fibers, and restoration of skin appendages. Histological studies showed that already at the early stages (days 8–12), active regeneration of the dermis, epidermis, and skin appendages occurs within the scar area, accompanied by high fibroblast activity and the formation of a collagen matrix. However, at later stages (days 21–25), scar tissue acquires a microscopic structure that closely approximates that of intact skin. This enables an objective assessment of the stages and completion of the healing process and, consequently, the determination of the age of injury, which constitutes the subject of forensic veterinary examination. Examination of skin scars under ultraviolet radiation on day 14 allows the detection of weakly expressed or absent fluorescence of scar tissue, which is due to the insufficient accumulation of mature collagen, despite the already relatively ordered orientation of collagen bundles. Wound healing in dogs occurs more rapidly and intensively than in cats, which is manifested by a more pronounced inflammatory response, more active neoangiogenesis, higher fibroblastic activity, and faster remodeling of scar tissue. An author-developed classification of skin scars, comprising 17 criteria, was created and formed the basis for forensic veterinary analysis aimed at assessing their impact on exterior disfigurement and mutilation of animals, as well as influencing the formulation of an accurate and comprehensive forensic veterinary diagnosis. The practical significance of the study lies in substantiating the objectives of forensic veterinary examinations of animals injured by sharp objects, particularly in the possibility of using a complex of macroscopic, histological, ultrasonographic, and luminescent scar features to establish the mechanism of trauma, the approximate age of injury, and to assess the degree of trauma-induced morphological and functional disorders in the organism.