Ultrasound Images Associated with Snakebites in a Japanese Black Calf

Snakebites are one of the leading causes of severe tissue necrosis in animals. Snakebite injuries can be diagnosed by their two distinct scars caused by the fangs. However, these wounds are rarely found in cattle because of their physical character. Therefore, the accumulation of an objective assessment, such as images diagnosis, in cattle is necessary. In this case, a 6-month-old male Japanese black calf showed sudden anorexia and swelling of the mandible; the animal died eight days after the onset of symptoms. On Day 1, the mandibular swelling was observed and body temperature was recorded as 41.5°C, and ptyalism was noted. The calf showed progressive swelling of the jaw and the dewlap. On Day 8, the calf was unconscious and died and a simplified necropsy was performed. The laboratory tests did not reveal any organ dysfunction or sepsis. Ultrasonography revealed subcutaneous edema, a cobblestone appearance characteristic of cellulitis and detachment between the subcutaneous and muscle tissue layers. The ultrasound imaging provided a diagnosis of cellulitis accompanied by necrosis of the deep fascial layer and also revealed detachment between the subcutaneous tissue and the muscle tissue with rapid enlargement of the affected area. Moreover, a subsequent necropsy proved that there was severe necrosis from the subcutaneous tissue to the fascia. The changes in the subcutaneous tissues were confirmed by simplified necropsy, and in this case were diagnosed as necrotizing cellulitis. The ultrasound images were able to provide the same diagnosis as the necropsy findings, which suggest that ultrasound imaging is valuable for the diagnosis of snakebite wounds in cattle. This case report provides valuable clarification about the use of ultrasound imaging of snakebites in cattle and ultrasonography could provide the essential information needed to diagnose and treat the animal.