Central Vestibular Disease in a Blue and Gold Macaw (Ara ararauna) With Cerebral Infarction and Hemorrhage

• Published in: Journal of avian medicine and surgery 2014-06, Vol.28 (2), p.132-142
• Main Authors: Grosset, Claire, Guzman, David Sanchez-Migallon, Keating, M. Kelly, Gaffney, Patricia M, Lowenstine, Linda, Zwingenberger, Allison, Young, Alex C, Vernau, Karen M, Sokoloff, Amberly M, Hawkins, Michelle G
• Format: Article
• Language: English
• Subjects: aneurysm; Animals; Ara ararauna; Atherosclerosis; avian; bird; Bird Diseases - pathology; Birds; Blood vessels; blue and gold macaw; Brain; Case studies; Cerebral hemispheres; Cerebral Hemorrhage - pathology; Cerebral Hemorrhage - veterinary; Cerebral Infarction - pathology; Cerebral Infarction - veterinary; Clinical Report; Clinical Reports; Diagnosis; Fatal Outcome; Female; Health aspects; Hemorrhage; Infarction; ischemic stroke; Lesions; Macaws; Magnetic Resonance Imaging; Midbrain; Parrots; Psittaciformes; Strokes; vestibular disease; Vestibular diseases
• ISSN: 1082-6742; 1938-2871
• DOI: 10.1647/2012-069

A 24-year-old female blue and gold macaw (Ara ararauna) was presented for an acute onset of left head tilt. On examination, the macaw was dehydrated and had a 120-degree left head tilt, decreased proprioception of the left pelvic limb, and intermittent vertical nystagmus. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with lymphopenia and heterophilia and a high uric acid concentration. Radiographs showed bilateral intertarsal joint osteoarthritis and a healed ulnar fracture. Magnetic resonance imaging of the brain revealed focal T2 and fluid-attenuated inversion recovery hyperintense lesions in the right cerebral hemisphere and in the midbrain. The midbrain lesion showed susceptibility artifact on the T2* sequence, suggesting hemorrhage. In the T2* sequence, iron accumulation (as seen with hemorrhage) distorts the magnetic signal, resulting in the production of a susceptibility artifact, which can then be visualized as a region of hypointensity. The bird was hospitalized but died despite intensive care. Necropsy revealed multiple cerebral vascular lesions including an acute cerebral infarct, a ruptured midbrain aneurysm, and multifocal systemic atherosclerosis. To our knowledge, this is the first report of a cerebral aneurysm in a bird. This report correlates the clinical presentation, imaging, and histopathologic findings in a macaw with central vestibular disease and demonstrates how advanced imaging techniques can identify hemorrhagic lesions through the T2* sequence.