Pathological Changes and Sodium Rhodizonate Test as Tools for Investigating Gunshot Wounds in Veterinary Forensic Pathology.

Gunshot wound morphology and gunshot residues (GSRs) evaluation have been poorly investigated in veterinary forensic pathology. The aims of the present study were to assess the gunshot wound morphology in animals and evaluate the detectability of lead deriving from GSRs using colorimetric techniques. To these aims, cadavers were divided into four different groups. Group A comprised eight animals who died from firearm-related injuries, while groups B and C included dog limbs shot using different shooting ranges; group D comprised dog limbs stabbed with a screwdriver. Morphological analysis was performed on all entry gunshot wounds. Lead residues were investigated using a Bullet Hole Testing Kit (BTK) and Rhodizonate Sodium histochemical staining (NaR-s). Gunshot wounds in group A showed an abrasion ring associated with hemorrhages and tissue necrosis. Groups B and C showed injuries related to the shooting range. NaR-s showed positive results in both animals that died from gunshot wounds and experimentally shot limbs. However, the number of positive cases and the pattern of lead distribution varied with the shooting range. Positive results by BTK were limited to close-contact shots in group B limbs. Our results suggest that both pathological examination and NaR tests represent valid tools for investigating gunshot wounds in veterinary pathology.

Pathological alterations and COHb evaluations as tools for investigating fire-related deaths in veterinary forensic pathology.

Fire-related deaths are usually a consequence of carbon monoxide (CO) poisoning or shock from thermal injuries. In humans, high levels of carboxyhemoglobin (COHb) concentrations in the blood can support a diagnosis of CO poisoning. In veterinary medicine, few studies investigated the pathological changes and blood COHb% in fire victims, and no data are available on post-mortem changes in blood gas composition due to fire. This study aims to investigate the pathological changes and COHb levels in both animal victims of fire and cadavers experimentally exposed to fire. For this purpose, dogs were selected and subdivided into three groups. Group A comprised 9 adult dogs, and Group B comprised 7 puppies that died under fire-related conditions. Group C was represented by 4 dog cadavers experimentally exposed to heat and smoke. A complete macroscopic, histological, and COHb evaluation were performed on each animal. Animals in Groups A and B showed cherry-red discoloration, thermal-injuries and soot deposits along the respiratory tract. Animals in Group C showed thermal injuries and soot deposits limited to the upper respiratory tract. The mean COHb% values in cadavers in Group C were lower than those observed in the other groups but higher compared to the values detected before the heat and smoke treatment. These findings suggest that both pathological changes and COHb analysis are valid tools for investigating fire-related deaths in dogs. However, the increase of COHb levels in cadavers exposed post-mortem to heat and smoke highlights how the COHb analysis should always be evaluated together with macroscopical and microscopical findings to avoid significant misjudgments in investigating fire-related fatalities in veterinary forensic practice.