Arachnoid cyst in a dog: case report

ABSTRACT Medullary arachnoid cyst (MAC) is a disease that occurs in humans and animals, and may cause neurological clinical signs. The origin of this disease, as well as its pathophysiology, are still unknown. It is believed that it can be congenital or acquired. No predilection for race, sex, or age has been verified. The aim of this paper is to report a lumbar MAC case in a dog at 13 years of age that caused paralysis of the pelvic limbs. At the clinical examination the patient had back pain on the lumbar region, urinary and fecal incontinence, and paraplegia on the pelvic members. The symptoms were progressing for eight months with history of trauma. In myelography a MAC in the lumbar region (L1- L2) lateralized to left was identified. For treatment laminectomy and durectomy were established. The patient showed improvement of clinical signs eleven days after surgery. The surgical treatment achieved good results for this type of disease. MAC can occur in geriatric or member paraplegia dogs, so it must be included in the differential diagnosis list of the lumbar compressive myelopathy.