A Practical Diagnostic Approach to Non-Drowning Asphyxia in Animals: Forensic Pathology and Biomarkers

The term asphyxia refers to a disruption in brain function due to rapid and persistent cerebral hypoxia or anoxia as a consequence of accidental or non-accidental injury. Considering the different mechanisms that may determine asphyxiation, such injuries can be referred to different categories: strangulation (death by hanging, ligature or manual strangulation), suffocation (smothering, choking, confined spaces and vitiated atmosphere), mechanical asphyxia (positional and traumatic asphyxia) and drowning (submersion or immersion in liquid). In both human and veterinary forensic practice, fatal asphyxia is considered among the most diagnostically challenging categories of sudden death, as it often produces only subtle and non-pathognomonic macroscopic signs, which can be easily covered by post-mortem alterations. Therefore, a wide range of information is often needed for the diagnosis of asphyxiation, including medical history, crime scene analysis, testimonies and physical evidence, along with the macroscopic and histological findings. The following review addresses the main lesions, ancillary tests and diagnostic issues associated with non-drowning asphyxia in veterinary forensic pathology.