Recovery after inadvertent intramedullary microchip implantation at C1–C2 in a kitten

Abstract

Case summary A 15-week-old male British Shorthair cat was presented for peracute paralysis immediately after microchip implantation. Neurological examination revealed a non-ambulatory tetraparesis and left thoracic limb plegia localised to C1–C5 spinal cord segments. CT of the cervical spine showed a diagonally orientated metallic foreign body (microchip transponder, 10 mm in length) within the vertebral canal at the level of C1–C2, resulting in a penetrating spinal cord injury. Based on concerns about further iatrogenic spinal cord injury through surgery, medical management was chosen. Despite the severe clinical signs, the kitten returned to ambulation within 6 days of the injury, with controlled urination and defecation. Continuous neurological improvement was seen for up to 6 weeks after the injury at which point a mild-to-moderate ambulatory tetraparesis and ataxia remained, with an overall good quality of life. Follow-up CT at the age of 13 months revealed a relative cranial displacement and rotation of the microchip towards the foramen magnum, while the cat’s neurological status was unchanged. Relevance and novel information This case demonstrated a cervical penetrating spinal cord injury in a growing cat caused by a microchip, which was successfully managed with medical treatment, suggesting that this might be an option for patients at risk of severe surgery-related complications or where owners reject surgery.

Pulmonary arterial embolism due to aberrant migration of a microchip in two dogs

“…Biocompatible material aims at reducing the local immune response to a fibrotic capsule 2 . Abnormal placement of the microchip can result in focal trauma, most commonly involving the spinal canal when implanted in the interscapular region 3–6 . These iatrogenic lesions are more likely to occur in unsedated, agitated dogs or cats.…”

“…2 Abnormal placement of the microchip can result in focal trauma, most commonly involving the spinal canal when implanted in the interscapular region. [3][4][5][6] These iatrogenic lesions are more likely to occur in unsedated, agitated dogs or cats. There has been one case report of progressive cervical vertebral lysis due to the microchip 3 years after implantation, which led to clinical neurological signs requiring surgical removal.…”

Preliminary report of spinal cord injuries resulting from inappropriate microchip implantation in two puppies

“…The two cases in this report were presented with acute onset of paresis following inappropriate microchip implantation. Similarly, there has been at least five reports of inappropriate implantation of microchip which caused spinal cord injuries, of which three cases were in dogs, and 2 cases in cats [ 4 , 5 , 12 , 13 , 15 ]. These iatrogenic spinal cord injuries are often presented as acute onset of ambulatory or non-ambulatory tetraparesis following the microchip implantation.…”