A novel spongiform leukoencephalomyelopathy in Border Terrier puppies.

Dog 1 was a 3-week-old male Border Terrier puppy referred to the Neurology and Neurosurgery Service of the Veterinary Medical Center, The Ohio State University, for ataxia and tremors. The signs were first noticed 5 days before presentation when the puppy first attempted to walk on its own. The owners reported that the tremors affected mainly the hindquarters. No improvement or worsening of the tremors had been noted over this period. An injectable corticosteroid (unknown type and dose) had been administered 4 days before referral, with no changes in the clinical signs. The tremors were reported to disappear when the puppy was sleeping. There were 3 other puppies from the same litter, which were reported to be normal, as were the parents. On presentation, the puppy showed severe generalized coarse body tremors (with low frequency and high amplitude), most severe in the hindquarters, which showed a characteristic swinging side-to-side or “rocking horse” movement (as illustrated in the supplementary Video S1). The tremors also involved the head and thoracic limbs, but to a lesser degree, and disappeared when the dog was asleep or at rest. Cerebellar ataxia was noted when the dog was trying to walk. The neurological examination was difficult because of the severity of the tremors, but it showed an absent menace bilaterally (considered normal for a 3-week-old puppy), delayed proprioceptive positioning, and hopping that was slightly hypermetric on all limbs. The remaining cranial nerves, spinal reflexes, cutaneous trunci reflex, and vertebral column palpation were unremarkable. Physical examination was within normal limits. Because the characteristics of the tremors, which were coarse and affected mainly the hindquarters, a diffuse or multifocal CNS disorder such as a congenital disorder of myelination was considered the main differential diagnosis. A cerebellar lesion (infectious or inflammatory cerebellar disease, cerebellar hypoplasia, neonatal cerebellar ataxia) also was considered possible, although less likely, based on the type of tremors noted. A complete blood count (CBC) and biochemical profile showed changes considered normal for a puppy. The owners, who also were the breeders, chose humane euthanasia. A complete necropsy was performed. A cerebrospinal fluid (CSF) sample was collected from the cerebellomedullary cistern immediately after euthanasia. The fluid was colorless and clear, with a total protein of 55 mg/ dL (reference range, <25 mg/dL), a white blood cell (WBC) count of 34 cells/lL (reference range, <5 cells/ lL) and a red blood cell (RBC) count of 452 cell/lL (reference range, <5 cells/ll). On cytology, there were 91% large mononuclear cells, 8% lymphocytes and 1% nondegenerate neutrophils. Occasional ependymal cells were noted and considered an incidental finding. The findings were consistent with a mild-to-moderate nonsuppurative pleocytosis and mild blood contamination. In addition, a urine sample was collected by cystocentesis immediately after euthanasia and sent to University of Pennsylvania for a metabolic screening panel. Results of the metabolic panel indicated increased aminoaciduria, increased lactate, increased hydroxy-lysine-glycoside, and a strongly positive response to mucopolysaccharides (MPS) spot test. The aminoaciduria was interpreted as an age-related finding. The increased lactate and strong positive MPS spot test were interpreted as suggestive of a defect in intermediary metabolism, possibly consistent with a metabolic disorder. Three other Border Terrier puppies, dogs 2–4, had a similar history and presentation. They were presented to one of the authors (KHJ) at the Swedish University of Agricultural Sciences, Uppsala, Sweden (dogs 2 and 3) and the Norwegian School of Veterinary Science in Oslo, Norway (dog 4). These puppies were two 6-week-old female littermates and one 5-week-old From the Department of Veterinary Clinical Sciences (MartinVaquero, da Costa) and the Department of Biosciences, College of Veterinary Medicine (Simmons, Beamer, Oglesbee), The Ohio State University, Columbus, OH; and the Department of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo, Norway (Jäderlund). This work was performed at the College of Veterinary Medicine, The Ohio State University, Columbus, OH. This article was presented in part as a Research Report at the 2011 American College of Veterinary Internal Medicine (ACVIM) Forum, Denver, Colorado. Corresponding author: P. Martin-Vaquero, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L. Tharp Street, Columbus, OH 43210; e-mail: [email protected] Submitted September 7, 2011; Revised November 24, 2011; Accepted December 14, 2011. Copyright © 2012 by the American College of Veterinary Internal Medicine 10.1111/j.1939-1676.2011.00873.x Abbreviations: