title: Pathological and electrophysiological features of a canine cone-rod dystrophy in the miniature longhaired dachshund.
abstract: OBJECTIVE
  To characterize the electrophysiological and histopathological features of a retinal degenerative disease in a colony of miniature longhaired dachshunds known to have a form of progressive retinal atrophy (PRA).
  
  
  METHODS
  Serial electroretinograms were recorded from affected homozygous (n = 36) and heterozygous (n = 15) dogs. Morphologic investigations including immunohistochemistry and lectin histochemistry were performed on selected homozygous animals (n = 15).
  
  
  RESULTS
  Clinical findings included loss of tapetal hyperreflectivity. The mode of inheritance was autosomal recessive. An early dramatic reduction of cone-specific ERG amplitude with a more modest reduction in rod b-wave amplitude was demonstrated. Progressively, rod specific responses diminished until there were no recordable responses to the ERG stimuli at 40 weeks of age. Morphologic changes confirmed early cone inner and outer segment loss. Other abnormalities included opsin mislocalization and outer nuclear layer thinning due to the subsequent loss of rod photoreceptors.
  
  
  CONCLUSIONS
  A novel canine cone-rod dystrophy has been identified.
authors.affiliation: UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Clare
authors.initials: C
authors.lastname: Turney
authors.forename: N H Victor
authors.initials: NH
authors.lastname: Chong
authors.forename: Robert A
authors.initials: RA
authors.lastname: Alexander
authors.forename: Chris R
authors.initials: CR
authors.lastname: Hogg
authors.forename: Lorraine
authors.initials: L
authors.lastname: Fleming
authors.forename: Deborah
authors.initials: D
authors.lastname: Flack
authors.forename: Keith C
authors.initials: KC
authors.lastname: Barnett
authors.forename: Alan C
authors.initials: AC
authors.lastname: Bird
authors.forename: Graham E
authors.initials: GE
authors.lastname: Holder
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Luthert
mesh_terms: D000818:Animals; D002452:Cell Count / Q000662:veterinary; D004283:Dog Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D004285:Dogs; D003576:Electron Transport Complex IV / Q000378:metabolism; D004596:Electroretinography / Q000662:veterinary*; D005260:Female; D005808:Genes, Recessive; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006651:Histocytochemistry / Q000662:veterinary; D007124:Immunoenzyme Techniques / Q000662:veterinary; D008297:Male; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism / Q000473:pathology*; D012160:Retina / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D017299:Rod Opsins / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D017299:Rod Opsins; D016708:Synaptophysin; D003576:Electron Transport Complex IV