title: Restored vision in a young dog following corticosteroid treatment of presumptive hypophysitis.
abstract: BACKGROUND
  Hypophysitis is an umbrella term for a group of disorders involving inflammation of the pituitary gland. A rare occurrence in humans, hypophysitis can produce a range of clinical signs including (but not limited to) visual deficits and diabetes insipidus. Only five cases of canine hypophysitis exist in the literature, all presenting in mature dogs with no visual deficits and a grave outcome. This case report describes the clinical and advanced imaging features of blindness-inducing presumptive hypophysitis in a dog, which rapidly resolved with medical management.
  
  
  METHODS
  A 1-year-and-seven-month-old neutered male Standard Poodle presented with subacute blindness, ataxia, and polyuria/polydipsia (PUPD). Magnetic resonance imaging (MRI) detected a contrast-enhancing pituitary mass with perilesional oedema compromising the optic chiasm. Suspecting neoplasia, anti-inflammatory corticosteroid was commenced prior to radiation therapy planning. Complete resolution of neurological and visual deficits occurred within 12 days of starting steroid treatment. Repeated advanced imaging indicated macroscopic resolution of the lesion. An extended thyroid panel with insulin-like growth factor-1 analysis supported a diagnosis of hypophysitis. Resolution of PUPD was achieved with tapering courses of prednisolone and desmopressin; the dog has since been clinically normal for 14 months and treatment-free for 11 months.
  
  
  CONCLUSIONS
  To the authors' knowledge, this is the first instance in which a canine pituitary mass has demonstrated long-term resolution with palliative medical treatment alone, alongside reversal of associated blindness and presumptive diabetes insipidus. We suspect this lesion to be a form of hypophysitis, which should be included among differential diagnoses for pituitary masses, and for subacute blindness in dogs. Where possible, we advocate biopsy-confirmation of hypophysitis prior to timely intervention with anti-inflammatory treatment.
authors.affiliation: Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK. nina.rzechorzek@ed.ac.uk.|Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG, UK. nina.rzechorzek@ed.ac.uk.
authors.forename: Nina Marie
authors.initials: NM
authors.lastname: Rzechorzek
authors.affiliation: Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG, UK.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Liuti
authors.affiliation: The Neurology Service, Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Garscube Campus, Bearsden Road, Glasgow, G61 1QH, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Stalin
authors.affiliation: Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG, UK.
authors.forename: Katia
authors.initials: K
authors.lastname: Marioni-Henry
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000818:Animals; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D000072659:Hypophysitis / Q000150:complications / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D016896:Treatment Outcome; D014786:Vision Disorders / Q000188:drug therapy / Q000209:etiology / Q000662:veterinary*
chemical_list: D000305:Adrenal Cortex Hormones
keywords: Central blindness; Hypophysitis; Insulin-like growth factor-1; Magnetic resonance imaging; Pituitary tumour; Standard Poodle