Domestic Animal Bites in Infants: Potential Risk of Fatal Maltreatment

Domestic dogs are popular worldwide, and dog bites cause significant morbidity in children and remain a public health problems. Approximately 1% of emergency department visits are for treatment of animal bites, and we encounter domestic animal-related injuries ranging from insignificant scratches to life-threatening injuries. Ownership of indoor pets such as dogs and cats has recently gained popularity in Japan. With this, the incidence of domestic animal-related injuries in infants has also increased. Here we describe the cases of two infants with severe domestic animal-related injuries sustained inside their homes, in the last 2 years. The ethics committee of Tokyo Medical University Hachioji Medical Center approved the design of this study (H-249). Patient 1, a previously healthy 10-month-old girl, was bitten on the head from the rear by a male dog while she was crawling in her grandfather’s house (Fig. 1a). The dog was a golden retriever, and there was no adult supervision at the time of the incident. Although there was a large amount of blood on the floor, there was little bleeding from the scar. Initial paramedic examination was as follows: Glasgow coma scale score, E1V1M1; blood pressure (BP), not measurable; carotid artery, palpable; heart rate (HR), 180 beats/min; and respiratory rate, 24 breaths/min. Her state of consciousness gradually deteriorated, and she had cardiopulmonary arrest (CPA) during transportation. Spontaneous circulation was achieved 41 min after onset, and the cause of CPA was considered hemorrhagic shock. Normal saline (NS) and blood transfusion were started, but the patient had a recurrent CPA and died. Patient 2 was a 7-month-old boy who had been bitten on the fingers by the pet cat in the presence of his mother, while he was sleeping. He had been bitten on the arm by the same cat 2 months previously, but no preventive measures had been implemented. His vital signs were as follows: BP, 80/40 mmHg and HR, 190 beats/min. He looked pale and presented with cold extremities. The patient had lost both of his fifth fingers and had a crush wound of the left second finger (Fig. 1b). Notably, HR improved after rapid boluses of NS and blood transfusion. Further, ampicillin/sulbactam and a polysaccharide-tetanus toxoid conjugate vaccine were given. The wounds were irrigated with NS, necrotic tissue was debrided under midazolam, and the wounds were covered with moist dressings. Immediately after the initial treatment, the patient was transferred to an advanced care hospital for children. Most dog-related injuries in Japan occur outdoors and <1% are fatal, and there have been no reports concerning life-threatening domestic animal-related injuries. We treated two cases of domestic animal-related injuries that led to substantial blood loss, especially one of which (case 1) involved CPA, possibly due to hemorrhagic shock. Massive bleeding associated with wounds in infants warrant emergency intervention. The major risk factors for dog bites involving the head or neck injuries include younger age, male sex, and a breed of dogs with a proclivity for biting; unfortunately patient 1 had these risk factors, but the family did not take any preventive measuresFurthermore, patient 2 was bitten on his extremities previously, which is major a risk factor for cat bites, and hence the cat needed to be prevented from getting close to the infant. Although counseling children and families about preventable pet-related injury is beneficial, the actual rate of providing guidance is low. Another problem is that it is the owner’s responsibility to report animal bites only to local public health center in Japan, whereas in the USA animal bites are required to be reported to state boards of health. We also experienced that the animal injuries sustained occurred regardless of witness being present. Therefore, we reported this case to the child maltreatment prevention team at the hospital and to the child consultation center as a suspected case of child maltreatment. We suggest that if physicians have diagnosed and performed interventions for pediatric animal bites, they have a responsibility to file a notification with the child maltreatment prevention team to alert them to suspected cases of child maltreatment and to prevent further injuries. Furthermore, publication of emergency physician experience with larger patient cohorts would provide valuable information on life-threatening but preventable domestic animal injuries, and facilitate identification of the risk factors for fatality.