This paper describes the clinical and histopathological features of a 16-year-old Cob mare who sustained a hemorrhagic cerebrovascular accident or stroke. The mare presented with an acute onset of neurological signs, with a neuroanatomical localization to the midbrain and thalamus regions. The mare was reported to have suffered from ataxia on all 4 limbs which started 7 days prior to referral, she was also showing several signs of left-sided cranial nerves deficits. On initial examination, the mare presented with quadrilateral ataxia, left-sided facial paralysis, weak tongue tone and a left-sided nose tilt as well as a hemineglect syndrome characterized by an inability to eat food presented on the right side of her mouth. Complete blood count and biochemistry analyses did not reveal any abnormalities, and a standing head CT revealed the presence of a hyperdense lesion localized in the left ventral cortex and thalamus region, which could be consistent with a vascular lesion, cholesterol granuloma or a mass. The mare was monitored, and as her condition slightly improved, she was discharged from the Hospital. Four weeks later, the clinical signs recurred and as the ataxia presented a danger for the mare and anyone handling her, the decision was made to euthanize her. A post-mortem CT scan of the head revealed an enlargement of the previous lesion, and the histopathological examination confirmed the presence of a hemorrhage within the brain, associated with neoplastic emboli. Hemorrhagic stroke has not previously been well described in horses therefore presents a challenge in diagnosis. Treatment in small animals is mainly conservative.

This case report describes successful conservative management of a comminuted fracture of the atlas. To the authors knowledge, fracture of the atlas in the horse and intrathecal corticosteroid injection in the standing sedated patient has not been previously reported. Clinical signs included acute onset ataxia, proprioceptive deficits and neck stiffness; which developed immediately post trauma during assisted recovery from general anaesthesia. Radiographic examination was not diagnostic immediately post trauma and computed tomographic (CT) imaging subsequently identified a fracture of the atlas. Treatment included ultrasound guided intrathecal medication of the cerebrospinal fluid and intra-articular medication of the atlantooccipital joint under standing sedation. Medication resulted in a marked improvement in clinical signs (grade 4 ataxia to grade 1 ataxia).