title: Spinal Cord Hamartomatous Myelodysplasia in 2 Horses With Clinical Neurologic Deficits.
abstract: Two horses euthanized for neurologic deficits were diagnosed with hamartomatous myelodysplasia of the spinal cord. One was a 5-week-old Holsteiner colt exhibiting spasms of muscle rigidity in the extensor muscles of the limbs and epaxial muscles, and the other was a 3-year-old Thoroughbred colt exhibiting progressive ataxia and hypermetria in the pelvic limbs. Each had focal disorganization of the white and gray matter of the spinal cord forming a mass interspersed with neurons, glial cells, and disoriented axon bundles. In the Holsteiner colt, the mass was at the level of C5 and included islands of meningeal tissue contiguous with the leptomeninges. The mass occluded the central canal forming hydromyelia cranial to the occlusion. In the Thoroughbred colt, the mass was at the level of L1 on the dorsal periphery of the spinal cord and did not involve the central canal.
authors.affiliation: Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA ky.t@ufl.edu.
authors.forename: K R
authors.initials: KR
authors.lastname: Taylor
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: MacKay
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Nelson
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Stieler
authors.affiliation: Thompson Bishop Sparks State Diagnostic Laboratory, Auburn, AL, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Roberts
authors.affiliation: Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: W L
authors.initials: WL
authors.lastname: Castleman
mesh_terms: D000818:Animals; D001259:Ataxia / Q000473:pathology / Q000662:veterinary; D006222:Hamartoma / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D006614:Hindlimb / Q000473:pathology; D006734:Horse Diseases / Q000175:diagnosis* / Q000473:pathology; D006736:Horses; D009436:Neural Tube Defects / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D013035:Spasm / Q000473:pathology / Q000662:veterinary; D013116:Spinal Cord / Q000473:pathology
keywords: ataxia; hamartoma; horse; hydromyelia; muscle spasm; myelodysplasia; spinal cord