Oral vitamin E absorption in English Cocker Spaniels with familial vitamin E deficiency and retinal pigment epithelial dystrophy.

Gillian McLellan // Publications // Sep 01 2012

PubMed ID: 22831287

Author(s): McLellan GJ, Bedford PG. Oral vitamin E absorption in English Cocker Spaniels with familial vitamin E deficiency and retinal pigment epithelial dystrophy. Vet Ophthalmol. 2012 Sep;15 Suppl 2:48-56. doi: 10.1111/j.1463-5224.2012.01049.x. Epub 2012 Jul 25. PMID 22831287

Journal: Veterinary Ophthalmology, Volume 15 Suppl 2, Sep 2012

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.

ANIMALS STUDIED 8 RPED-affected ECS and five clinically normal dogs.

PROCEDURES 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.

© 2012 American College of Veterinary Ophthalmologists.