title: Oral vitamin E absorption in English Cocker Spaniels with familial vitamin E deficiency and retinal pigment epithelial dystrophy.
abstract: BACKGROUND
  Retinal Pigment Epithelial Dystrophy (RPED) with neuroaxonal degeneration in English Cocker Spaniels (ECS) is associated with systemic vitamin E deficiency in the absence of dietary insufficiency.
  
  
  OBJECTIVE
  To evaluate the ability of ECS with RPED to absorb orally administered vitamin E and establish a basis for vitamin E supplementation in affected dogs.
  
  
  METHODS
  8 RPED-affected ECS and five clinically normal dogs.
  
  
  METHODS
  An oral vitamin E tolerance test (OVETT) was conducted in each dog. Blood samples were obtained prior to and at 3, 6, 9, 12, 24, 120, and 240 h following oral administration of 90 iu/kg of RRR-α-tocopherol. Plasma alpha tocopherol (αTOC) content was measured by normal phase, high-performance liquid chromatography, and indices of vitamin E absorption calculated.
  
  
  RESULTS
  There was marked variation in OVETT results between individuals. In RPED-affected ECS, mean peak plasma αTOC concentration (17.87 ± 13.21 μg/mL), attained after administration of a large oral dose of the vitamin, was significantly lower than the mean peak plasma αTOC concentration attained in normal dogs (47.61 ± 17.17 μg/mL; P < 0.005). However, the plasma concentrations achieved in 7/8 RPED-affected dogs remained within the normal reference range for plasma αTOC in vitamin E-replete dogs, for at least 12 h postdose.
  
  
  CONCLUSIONS
  Vitamin E-deficient ECS with RPED are capable of absorbing orally administered vitamin E. Twice daily administration of 600-900 iu tocopherol is likely to restore plasma vitamin E concentrations to the normal range in most affected dogs.
authors: Department of Small Animal Medicine and Surgery, Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK. mclellan@vetmed.wisc.edu
authors: Gillian J
authors: GJ
authors: McLellan
authors: Peter G C
authors: PG
authors: Bedford
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D004283:Dog Diseases / Q000097:blood / Q000378:metabolism*; D004285:Dogs; D005260:Female; D008297:Male; D012163:Retinal Detachment / Q000235:genetics / Q000378:metabolism / Q000662:veterinary*; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D014811:Vitamin E Deficiency / Q000188:drug therapy / Q000235:genetics / Q000662:veterinary*
chemical_list: D014810:Vitamin E