Forensic Death Investigations of Dog Bite Injuries in 31 Cats

SIMPLE SUMMARY: Fatal dog bite injuries are common in free-ranging cats in Taiwan. The causes of death of these cats are sometimes speculated to be animal cruelty by the general public. To persuade the public and ease speculation, we document and summarize the features of dog bite injuries and further develop a method for canine DNA identification. Performing forensic necropsies on 31 cats with dog bite injuries, we found that puncture wounds, linear or small, round contusions/abrasions, and lacerations/avulsions are characteristic bite-related injuries. A preference for specific body regions was not observed. Using DNA samples from wound swabs and hair remains, we identified canine DNA in 27.3% of cases. This study provides an applicable method for canine DNA identification in cats and reference data for future veterinary forensic investigations of dog bite injuries. ABSTRACT: Animal bite injuries are common in free-ranging cats in Taiwan, and most fatal animal bite events are presumed to be caused by dogs. However, speculation regarding animal abuse may occur when carcasses with prominent injuries are found by members of the general public. Local animal protection offices and veterinary clinicians sometimes face difficulties in convincing these individuals by identifying specific features of dog bite injuries in cat carcasses. Therefore, the present study analyzed injury patterns and distribution in 31 necropsied cats with animal bite injuries, and applied deoxyribonucleic acid (DNA) analysis for canine DNA identification in 13 cats. The main necropsy findings included puncture wounds (26 (83.9%)), linear or small, round contusions/abrasions (20 (64.5%)), lacerations/avulsions (17 (54.8%)), abdominal wall rupture/laceration (19 (61.3%)), herniation (16 (51.6%)), fractures (21 (67.7%)), broken claws (16 (51.6%)), and hair tufts on the body surface (28 (90.3%)). The most-commonly injured regions were the ventral thorax and axilla (23 (74.2%)), hind limbs (22 (71.0%)), shoulder-to-dorsal thorax (21 (67.7%)), back and flank (20 (64.5%)), abdomen (19 (61.3%)), neck (19 (61.3%)), and hip/tail/perineum (17 (54.8%)). Canine mitochondrial DNA was identified in 3 out of 11 cases (27.3%) that were sampled using wound swabs and in 4 out of 5 cases that had hair entrapped in broken claws. In conclusion, this study determined the distribution and features of dog bite injuries in cats and developed an elemental method using trace evidence for DNA identification in animal bites.